Optical combiner with improved efficiency and uniformity

Abstract

Systems, devices, and methods for directing display light employ one or more optical combiners that include recycling optics, such as diffraction gratings, that can receive wasted display light traveling in the volume of the optical combiner and redirect the wasted display light toward other optics so that the wasted display light can be efficiently used to produce a display. The optical combiner can also include uniformizing optics that can redistribute non-uniform display light to produce a more uniform display, which in turn enables the use of more efficient optics.

Description

Background Art

[0001] Electronic devices are commonplace in much of the world today. Advances in integrated circuit technology have enabled the development of electronic devices that are small and light enough to be carried by a user. Such "portable" electronic devices may include an on-board power supply (such as a battery or other power storage system), and may be "wireless" (i.e., designed to operate without any wires connected to other non-portable electronic systems); however, a small and lightweight electronic device may still be considered portable even if it includes a wired connection to a non-portable electronic system. For example, a microphone may be considered a portable electronic device regardless of whether it operates wirelessly or via a wired connection.

[0002] The convenience brought by the portability of electronic devices has spawned a huge industry. Smartphones, audio players, laptops, tablet computers, and e-book readers are all examples of portable electronic devices. However, the convenience of being able to carry a portable electronic device also brings the inconvenience of the device itself weighing down a person's hands. This problem is solved by making electronic devices not only portable but also wearable.

[0003] A wearable electronic device is any portable electronic device that a user can carry without physically grasping, holding, or otherwise gripping the device with their hands. For example, a wearable electronic device may be attached or coupled to a user via one or more straps, one or more bands, one or more clips, adhesives, pins and buckles, a piece of clothing, a tension or elastic support, an interference fit, an ergonomic form, etc. Examples of wearable electronic devices include digital watches, electronic armbands, electronic rings, electronic ankle bracelets or "footbands", head-mounted electronic display units, hearing aids, etc.

[0004] Because they are worn on the user's body, are typically visible to others, and are typically present for extended periods of time, form factor (i.e., size, geometry, and appearance) is a major design consideration for wearable electronic devices.

[0005] A head-mounted display is an electronic device that is worn on a user's head and, when so worn, fixes at least one electronic display within the field of view of at least one eye of the user. A wearable heads-up display is a head-mounted display that enables the user to see the displayed content but also does not prevent the user from being able to see their external environment. The "display" component of a wearable heads-up display is either transparent or located at the periphery of the user's field of view, such that it does not completely block the user from seeing their external environment.

[0006] In near-eye optics such as rifle scopes and wearable heads-up displays, the range of eye positions (relative to the device itself) within which a user can see specific content / images provided by the device is often referred to as the "eyebox." Applications where content is visible only from a single or small range of eye positions have a "small eyebox," while applications where content is visible from a wide range of eye positions have a "large eyebox." The eyebox can be thought of as a volume in space located near the optics. When the user's eye (more specifically, the pupil of the user's eye) is within this volume and facing the device, the user is able to see all of the content provided by the device. When the user's eye is outside of this volume, the user cannot see at least some of the content provided by the device.

[0007] The eye zone is an important property that can greatly affect the user experience of a wearable heads-up display. For example, if a wearable heads-up display has a small eye zone centered on the user's pupil when the user is looking straight ahead, some or all of the content displayed by the wearable heads-up display may disappear when the user gazes slightly off-center (such as slightly to the left, slightly to the right, slightly up, or slightly down). Unless the wearable heads-up display is intentionally designed to provide a glanceable display (i.e., the display is not always visible, but only visible when the user is looking in a certain direction), it is generally advantageous for the wearable heads-up display to have a large eye zone.

[0008] In some embodiments of a wearable head-up display, a light engine is at least partially located outside of a user's field of view, and at least one display optical device is used to redirect light from the light engine to the user's eye to form a display visible to the user. An example is a waveguide combiner, where display light from the light engine is in-coupled into the volume of the waveguide combiner through an incoupler optical device. The display light then travels in the volume of the waveguide combiner into the user's field of view, and is then out-coupled from the volume of the waveguide combiner to the user's eye through an outcoupler optical device, thereby forming a display.

[0009] Such redirection optics may be inefficient because a significant portion of the display light output by the light engine may not be efficiently incoupled, outcoupled, or otherwise directed to form a visible display. As a result, the light engine will consume additional power to produce light that is not efficiently utilized, which may reduce battery life and / or require a larger battery. In addition, such a system may also require the light engine to be able to output additional bright light, which may require a larger light engine and / or a light engine that is subject to more stringent safety issues and regulations. In view of this, there is a need to improve the efficiency of redirection optics in wearable head-up displays to reduce the amount of display light required.

[0010] Redirecting optics such as those described above may produce a non-uniform display. There may be a tradeoff between optical efficiency and display uniformity, with the most uniform displays typically produced by relatively inefficient optics. Thus, there may also be a tradeoff between display power efficiency and display uniformity. It is therefore desirable to provide a display that can achieve high uniformity with minimal impact on efficiency. Summary of the invention

[0011] According to a broad form, the present disclosure describes an optical combiner that includes: an incoming coupler optic for receiving display light from outside the optical combiner and redirecting the display light to travel in a volume of the optical combiner; an outgoing coupler region for receiving display light traveling in the volume of the optical combiner, the outgoing coupler region including an outgoing coupler optic for redirecting a first portion of the display light traveling in the volume of the optical combiner to exit from the volume of the optical combiner, the outgoing coupler optic for allowing a second portion of the display light traveling in the volume of the optical combiner to pass through the outgoing coupler region without being redirected to exit from the volume of the optical combiner; and a first recycling optic for receiving the second portion of the display light and redirecting the second portion of the display light to travel in the volume of the optical combiner back toward the outgoing coupler region.

[0012] The optical combiner may further include an expander region for receiving display light from the incoming coupler optics, the expander region including an expander optic for redirecting the display light received from the incoming coupler optics toward the outgoing coupler region. The incoming coupler optics may redirect a third portion of the display light toward the expander region and may redirect a fourth portion of the display light away from the expander region, and the optical combiner may further include a second recycling optic for receiving the fourth portion of the display light and redirecting the fourth portion of the display light toward the expander region.

[0013] The expander optical device can redirect a third portion of the display light toward the outgoing coupler region, and can allow a fourth portion of the display light to pass through the expander region without being redirected toward the outgoing coupler region. The optical combiner can also include: a second recycling optical device, the second recycling optical device is used to receive the fourth portion of the display light that passes through the expander region without being redirected toward the outgoing coupler region, and the second recycling optical device is used to redirect the fourth portion of the display light toward the expander region, wherein the expander optical device can redirect the fourth portion of the display light from the second recycling optical device away from the outgoing coupler region; a third recycling optical device, the third recycling optical device is used to receive the fourth portion of the display light that is redirected by the expander optical device away from the outgoing coupler region, and the third recycling optical device is used to redirect the fourth portion of the display light toward the outgoing coupler region.

[0014] The incoming coupler optics, the outgoing coupler optics, and the first recycling optics may be surface relief gratings. The incoming coupler optics, the outgoing coupler optics, and the first recycling optics may be optical holograms. The outgoing coupler optics may be optical gratings, the first recycling optics may be optical gratings, and the first recycling optics may have a period that is half the period of the outgoing coupler optics.

[0015] The outgoing coupler optics may be a two-dimensional optical grating for receiving display light traveling in a first direction in the volume of the optical combiner, redirecting some of the display light traveling in the first direction in the volume of the optical combiner to travel through the volume of the optical combiner in a second direction that is not parallel to the first direction, and redirecting some of the display light traveling in the second direction through the volume of the optical combiner to exit from the volume of the optical combiner. Some of the display light traveling in the volume of the optical combiner in the first direction may pass through the outgoing coupler region without being redirected to travel in the second direction, some of the display light traveling in the second direction may pass through the outgoing coupler region without being redirected to exit from the volume of the optical combiner, and the optical combiner may further include a second recycling grating for receiving display light traveling in the second direction that passes through the outgoing coupler region and redirecting the received display light toward the outgoing coupler region.

[0016] The outgoing coupler optics and the first recycling optics may be directly adjacent to each other.The outgoing coupler optics and the first recycling optics may be spatially separated from each other by a gap.

[0017] According to another broad aspect, the present disclosure describes an optical combiner comprising: an incoming coupler optic for receiving display light from outside the optical combiner and redirecting the display light to travel in a volume of the optical combiner; an outgoing coupler optic for receiving display light traveling in the volume of the optical combiner and redirecting the display light traveling in the volume of the optical combiner to exit from the volume of the optical combiner; and a recycling optic for receiving display light traveling in the volume of the optical combiner in a direction away from the outgoing coupler optic and redirecting the display light traveling in the volume of the optical combiner in a direction away from the outgoing coupler optic toward the outgoing coupler optic.

[0018] The outgoing coupler optics may be positioned laterally between the incoming coupler optics and the recycling optics.

[0019] The incoming coupler optics may be positioned laterally between the recycling optics and the outgoing coupler optics.

[0020] The optical combiner may also include an expander optic for receiving the display light from the incoming coupler optic, the expander optic redirecting the received display light toward the outgoing coupler region.

[0021] The expander optics may be positioned laterally between the recycling optics and the outgoing coupler optics.

[0022] According to another broad aspect, the present disclosure describes an optical combiner comprising: an incoming coupler optic for receiving display light from outside the optical combiner and redirecting the display light to travel in a first direction in a volume of the optical combiner; an expander optic for receiving display light traveling in the first direction in the volume of the optical combiner and redirecting the display light to travel in a second direction in the volume of the optical combiner as a plurality of spatially separated display light portions, the second direction being non-parallel to the first direction; and a homogenizing optic for receiving display light traveling in the second direction in the volume of the optical combiner. The invention relates to a method of receiving at least one of the portions of spatially separated display light travelling in the volume of the optical combiner along the second direction received by the homogenizing optics, and for each portion of spatially separated display light travelling in the volume of the optical combiner along the second direction received by the homogenizing optics, the homogenizing optics is used to redirect a sub-portion of the portion of the spatially separated display light travelling in the volume of the optical combiner along the second direction to travel in the volume of the optical combiner along the first direction and then redirect the sub-portion to travel in the volume of the optical combiner along the second direction; and an exit coupler optics for receiving display light travelling in the volume of the optical combiner along the second direction and redirecting the display light to exit from the volume of the optical combiner.

[0023] Each of the incoming coupler optics, expander optics, homogenizing optics, and outgoing coupler optics may include a surface relief grating. Each of the incoming coupler optics, expander optics, homogenizing optics, and outgoing coupler optics may include an optical hologram.

[0024] The uniformizing optical device may include an optical grating, and the uniformizing optical device may have a first diffraction efficiency for a region of the uniformizing optical device close to the incoming coupler optical device, and the uniformizing optical device may have a second diffraction efficiency for a region of the uniformizing optical device far from the incoming coupler optical device, and the first diffraction efficiency is greater than the second diffraction efficiency.

[0025] The homogenizing optics may have a first width in the second direction for a region of the homogenizing optics close to the incoming coupler grating, and may have a second width in the second direction for a region of the homogenizing optics away from the incoming coupler grating, the first width being greater than the second width.

[0026] The expander optics and the homogenizing optics may be directly adjacent to each other. The expander optics and the homogenizing optics may be continuous grating regions. The expander optics and the homogenizing optics may be spatially separated by a gap. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present disclosure may be better understood, and its numerous features and advantages made apparent to those skilled in the art by referring to the accompanying drawings. The use of the same reference numerals in different drawings indicates similar or identical items.

[0028] Figure 1 is a partially cutaway perspective view of an exemplary wearable heads-up display (“WHUD”) in accordance with the present systems, apparatus, and methods.

[0029] Figure 2 is a top cross-sectional view of an exemplary WHUD in accordance with the present systems, apparatus, and methods.

[0030] Figure 3 is a top cross-sectional view of another exemplary WHUD in accordance with the present systems, apparatus, and methods.

[0031] Figure 4 is a top cross-sectional view of yet another exemplary WHUD in accordance with the present systems, apparatus, and methods.

[0032] Figure 5 is an orthogonal view of an optical combiner including incoming coupler optics, outgoing coupler optics, and recycling optics according to an exemplary embodiment.

[0033] Figure 6 is an orthogonal view of an optical combiner including incoming coupler optics, outgoing coupler optics, and recycling optics according to another exemplary embodiment.

[0034] Figure 7 is an orthogonal view of an optical combiner including an incoming coupler optic, an outgoing coupler optic, and a plurality of recycling optics, according to an exemplary embodiment.

[0035] Figure 8 is an orthogonal view of an optical combiner including incoming coupler optics, expander optics, outgoing coupler optics, and recycling optics according to an exemplary embodiment.

[0036] Fig. 9 is an orthogonal view of an optical combiner including an incoming coupler optic, an expander optic, an outgoing coupler optic, and two recycling optics, according to another exemplary embodiment.

[0037] Fig.10 is an orthogonal view of an optical combiner including incoming coupler optics, expander optics, outgoing coupler optics, and recycling optics according to yet another exemplary embodiment.

[0038] Fig.11 An orthogonal view of an optical combiner including an incoming coupler optic, an expander optic, an outgoing coupler optic, and a plurality of recycling optics according to an exemplary embodiment.

[0039] Fig.12 is an orthogonal view of an optical combiner including incoming coupler optics, outgoing coupler optics, and recycling optics according to an exemplary embodiment.

[0040] Fig.13 is an orthogonal view of an optical combiner including incoming coupler optics, expander optics, homogenizing optics, and outgoing coupler optics, according to an exemplary embodiment.

[0041] Fig.14 An orthogonal view of an optical combiner including an incoming coupler optic, an expander optic, a homogenizing optic, an outgoing coupler optic, and a plurality of recycling optics, according to an exemplary embodiment. DETAILED DESCRIPTION

[0042] In the following description, certain specific details are set forth in order to provide a thorough understanding of the various disclosed embodiments. However, those skilled in the relevant art will recognize that the embodiments can be practiced without one or more of these specific details, or using other methods, components, materials, etc. In other cases, well-known structures associated with portable electronic devices and head-mounted devices are not shown or described in detail to avoid unnecessarily obscuring the description of the embodiments.

[0043] Unless the context requires otherwise, in the following description and claims, the word "comprise" and variations such as "comprises" and "including" are to be interpreted in an open and inclusive sense, ie, "including, but not limited to."

[0044] Reference throughout this specification to "one embodiment" or "an embodiment" means that the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0045] As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the content clearly dictates otherwise. It should also be noted that the term "or" is generally used in its broadest sense, i.e., to mean "and / or," unless the content clearly dictates otherwise.

[0046] The titles and abstracts of the disclosure provided herein are for convenience only and do not interpret the scope or meaning of the embodiments.

[0047] Various embodiments described herein provide optical combiners with improved efficiency and / or display uniformity.

[0048] Figure 1 is a partially cut-away perspective view of an exemplary wearable head-up display ("WHUD") 100 in accordance with the present systems, devices, and methods. The WHUD 100 includes a first arm 110, a second arm 120, and a front frame 130 physically coupled to the first arm 110 and the second arm 120. When worn by a user, the first arm 110 will be positioned on a first side of the user's head, the second arm 120 will be positioned on a second side of the user's head opposite the first side of the user's head, and the front frame 130 will be positioned on the front side of the user's head. The first arm 110 carries a light engine assembly 111 that outputs light representing display content to be viewed by the user. For example, the first arm 110 may also optionally carry several additional components of the WHUD 100, such as at least one processor, at least one non-transitory processor-readable storage medium, or a power supply circuit. The front frame 130 carries an optical combiner 131 in the user's field of view that receives light output from the light engine assembly 111 and redirects the light to form a display for viewing by the user. In Figure 1 In this case, the display will be a monocular display visible to the user's right eye. Figure 1 The second arm 120 shown in the figure carries a power source 121 for powering the components of the WHUD 100. The front frame 130 also carries at least one set of conductive current paths 140 that provide electrical coupling between the power source 121 and the light engine 111 and any other electrical components carried by the first arm 110. As used herein, a "power source" can refer to a component that provides power. This can include, for example, a source of stored power such as a battery, including a chemical battery or a mechanical battery, or can include a power generation system such as a piezoelectric element, a solar cell, or the like. As used herein, a "set of conductive current paths" can refer to a single conductive current path, such as a wire or conductive trace on a printed circuit board, and multiple conductive current paths, such as multiple wires or multiple conductive traces on a printed circuit board. In addition, for a set of conductive current paths to provide electrical coupling, at least one current path in the set can provide coupling. It is possible, but not necessary, for multiple or all conductive current paths in the set to provide coupling. In addition, for a set of conductive current paths to provide electrical coupling to another set of conductive current paths, at least one current path in one set should be coupled to at least one current path in another set. Each conductive current path in one group may, but need not, be coupled to a corresponding conductive current path in another group. It is also possible that any group of conductive current paths may be used as a fan-in or fan-out path, where the number of conductors in one group of conductive current paths is greater or less than the number of conductors in another group of conductive current paths.

[0049] As an example, the orientation of WHUD 100 may be reversed so that the display is presented to the user's left eye rather than the right eye, as described later. Figure 3 As another example, the second arm 120 may carry a light engine assembly similar to the light engine assembly 111 carried by the first arm 110, and the front frame 130 may also carry an optical combiner similar to the optical combiner 131, so that the WHUD 100 presents a binocular display to both the right eye and the left eye of the user, as described later. Figure 4 shown.

[0050] The light engine assembly 111 and the optical combiner 131 may include any suitable display architecture for outputting light and redirecting light to form a display viewed by a user. For example, the light engine 111 and any light engine discussed herein may include at least one component selected from a group including at least one of the following: a projector, a scanning laser projector, a microdisplay, a white light source, or any other display technology suitable for a given application. The optical combiner 131 and any optical combiner discussed herein may include at least one optical component selected from a group including at least one of the following: a waveguide, at least one holographic optical element, at least one prism, a diffraction grating, at least one light reflector, an array of light reflectors, at least one light refractor, an array of light refractors, or any other light redirection technology suitable for a given application, and the at least one optical component is positioned and oriented to redirect the display light toward the user's eyes. The optical combiner 131 may be carried by a lens, and the lens may be carried by the front frame 130. For example, the optical combiner 131 may be: a layer formed as part of a lens, a layer adhered to a lens, a layer embedded in a lens, a layer sandwiched between at least two lenses, or any other suitable arrangement. The layer may be molded or cast, for example, and / or may include a film and / or coating. Alternatively, the optical combiner 131 may be a lens carried by the front frame 130. In addition, as used herein, a "lens" may refer to a flat lens that does not apply optical power and does not correct the user's vision, or a "lens" may be a prescription lens that applies optical power to incident light to correct the user's vision.

[0051] Exemplary display architectures may include, for example, a scanning laser projector and holographic optical element combination, an edge-lit light guide display, a pinlight display, or any other wearable heads-up display technology suitable for a given application.

[0052] The term "light engine" as used herein is not limited to referring to a single light source, but may also refer to multiple light sources, and may also refer to a "light engine assembly". The light engine assembly may include some components that enable the light engine to function or improve the operation of the light engine. As an example, the light engine assembly may include at least one light source, such as a laser or multiple lasers. The light engine assembly may additionally include electrical components such as a drive circuit to provide power to at least one light source. The light engine assembly may additionally include optical components such as a collimating lens, a beam combiner, or a beam shaping optical device. The light engine assembly may additionally include a beam redirection optical device, such as at least one MEMS reflector, which can be operated to scan light from at least one laser source in, for example, a scanning laser projector. In the above examples, the light engine assembly includes not only a light source, but also a component that obtains output from at least one light source and generates a conditioned display light. All components in the light engine assembly may be contained in a housing of the light engine assembly, may be attached to a substrate (such as a printed circuit board or the like) of the light engine assembly, or may be a separately mounted WHUD component.

[0053] The term "optical combiner" as used herein may also refer to an "optical combiner assembly". An optical combiner assembly may include additional components that support or enable the functionality of the optical combiner. As an example, a waveguide combiner may be very thin and therefore very fragile. To this end, it may be necessary to position the waveguide combiner within or on a transparent carrier such as a lens. The optical combiner assembly may be a package including a transparent carrier and a waveguide located therein or thereon. As another example, the optical combiner assembly may include a prescription component that applies a refractive power to the incident light to compensate for defective user vision. Such a prescription component may include a curvature applied to the transparent carrier itself, or may include a component attached to the transparent carrier, such as a clip-in or add-on lens.

[0054] Several exemplary WHUDs are described below, which further illustrate various features of the present systems, devices, and methods. It will be appreciated by those skilled in the art that the specific features described in the following embodiments may be appropriately combined, such that the present disclosure is not limited to the embodiments discussed below, but also includes any reasonable combination of features of the embodiments discussed herein.

[0055] Figure 22 is a top cross-sectional view of an exemplary WHUD 200 according to the present systems, devices, and methods. Similar to WHUD 100, WHUD 200 includes a first arm 210, a second arm 220, and a front frame 230. The first arm 210 is coupled to the front frame 230 via a hinge 219, which allows the first arm 210 to rotate relative to the front frame 230. The second arm 220 is coupled to the front frame 230 via a hinge 229, which allows the second arm 220 to rotate relative to the front frame 230. Figure 2 The WHUD 200 is shown in a non-folded configuration, wherein the first arm 210 and the second arm 220 are rotated so that the WHUD 200 can be worn on the user's head, and the first arm 210 is positioned on a first side of the user's head, the second arm 220 is positioned on a second side of the user's head opposite the first side, and the front frame 230 is positioned in front of the user's head. The first arm 210 and the second arm 220 can be rotated toward the front frame 230 until both the first arm 210 and the second arm 220 are substantially parallel to the front frame 230, so that the WHUD 200 will be in a compact shape that is conveniently mounted in an elongated rectangular, cylindrical, or elliptical housing.

[0056] exist Figure 2 , the first arm 210 carries the light engine assembly 211. The second arm 220 carries the power source 221. The front frame 230 carries the optical combiner 231 and at least one set of conductive current paths (not shown to avoid confusion). The terms "carry", "carrying" or similar terms used herein do not necessarily mean that one component physically supports another component. For example, it is mentioned above that the first arm 210 carries the light engine assembly 211. This may mean that the light engine assembly 211 is mounted to or installed within the first arm 210, so that the first arm 210 physically supports the light engine assembly 211. However, even when the first arm 210 does not necessarily physically support the light engine assembly 211, a direct or indirect coupling relationship can be described. As an example, in some embodiments, the hinge of the WHUD can support both the arm of the WHUD and the light engine of the WHUD, without a direct supporting relationship between the light engine and the first arm. This is true for any component relationship described herein, where one component "carries" another component.

[0057] At least one set of conductive current paths provides electrical coupling between the power source 221 and the electrical components carried by the first arm 210, such as the light engine assembly 211. This electrical coupling may be provided indirectly, such as through a power circuit, or may be provided directly from the power source 221 to each electrical component in the first arm 210.

[0058] In some embodiments, it is possible that when WHUD 200 is not in the unfolded configuration, the electrical coupling between the power source 221 and the electrical components in the first arm 210 can be disconnected. For example, WHUD 200 can include a safety switch that disconnects or disables the provision of power from the power source 221. As another example, when WHUD 200 is not in the unfolded configuration, at least one of the set of conductive current paths can be physically disconnected from other conductive current paths, electrical components, or the power source 221.

[0059] The light engine assembly 211 can output display light 290 representing display content to be viewed by the user. The display light 290 can be redirected by the optical combiner 231 to the user's eye 291 so that the user can see the display content. In the case of the WHUD 200, the optical combiner 231 is a waveguide combiner that includes an incoming coupler optic 231a and an outgoing coupler optic 231b. The display light 290 from the light engine assembly 211 illuminates the incoming coupler optic 231a and is redirected to travel in the volume of the waveguide combiner 231, where the display light 290 is guided through the waveguide, such as by total internal reflection or waveguide surface treatment (such as optical holography or reflective coating). Subsequently, the display light 290 traveling in the volume of the waveguide combiner 231 illuminates the outgoing coupler optic 231b, which redirects the display light 290 coming out of the waveguide combiner toward the user's eye 291.

[0060] WHUD 200, as well as any other WHUD discussed herein, may include at least one processor that is communicatively coupled to each electrical component in WHUD 200, including, but not limited to, light engine 211. The at least one processor may be any suitable component that can execute instructions or logic, including, but not limited to, a microcontroller, a microprocessor, a multi-core processor, an integrated circuit, an ASIC, an FPGA, a programmable logic device, or any suitable combination of these components. In addition, WHUD 200, as well as any other WHUD discussed herein, may include at least one non-transitory processor-readable storage medium that may store processor-readable instructions thereon, which, when executed by at least one processor, may cause at least one processor to perform any number of functions, including causing light engine 211 to output light 290 representing display content to be viewed by a user, receiving user input, managing a user interface, generating display content to be presented to a user, receiving and managing information from any sensors carried by WHUD 200, receiving and processing external data and messages, and / or any other functions applicable to a given application. At least one non-transitory processor-readable storage medium may be any suitable component that can store instructions, logic, or programs, including but not limited to non-volatile or volatile memory, read-only memory (ROM), random access memory (RAM), flash memory, registers, magnetic hard disks, optical disks, or any combination of these components.

[0061] Figure 3 is a top view of the WHUD300. The WHUD300 is similar to Figure 2 Unless the context clearly indicates otherwise, descriptions related to components of WHUD200 may apply to similarly numbered components of WHUD300. Figure 2 Similar to WHUD 200 shown in FIG, WHUD 300 can be transformed between a folded configuration and an unfolded configuration.

[0062] One difference between WHUD300 and WHUD200 is that the orientation of the components in WHUD300 is opposite relative to WHUD200. In particular, in WHUD200, the first arm 210 will be positioned on the right side of the user's head when worn, while the second arm 220 will be positioned on the left side of the user's head when worn. On the other hand, in WHUD300, the first arm 210 will be positioned on the left side of the user's head when worn, while the second arm 220 will be positioned on the right side of the user's head when worn. The light engine assembly 211 can output display light 292, which is directed by the optical combiner 231 toward the display light 292 as shown in FIG. Figure 3 The user's left eye 293 is redirected instead of Figure 2Redirection towards the right eye 291 is shown.

[0063] Reference Figure 3 The orientation reversal of the WHUD described in WHUD 300 is fully applicable to any WHUD described herein.

[0064] Figure 4 This is a top view of the WHUD400. The WHUD400 is similar to the Figure 2 Unless the context clearly indicates otherwise, descriptions related to components of WHUD200 may apply to similarly numbered components of WHUD400. Figure 2 Similar to WHUD 200 shown in FIG, WHUD 400 can be transformed between a folded configuration and an unfolded configuration.

[0065] One difference between WHUD400 and WHUD200 is that WHUD400 has binocular display functionality. That is, WHUD400 can present a display to both the user's eye 291 and eye 293. This can be achieved by including a first optical combiner 231 in front of the user's first eye 291 and positioning a second optical combiner 232 in front of the user's second eye 293. The first light engine assembly 211a carried by the first arm 210 can output display light 290 to the first optical combiner 231, which can redirect the light 290 toward the user's first eye 290 to form a display seen by the first eye 291. The second light engine assembly 211b carried by the second arm 220 can output display light 292 to the second optical combiner 232, which can redirect the light 292 toward the user's second eye 293 to form a display seen by the second eye 293.

[0066] Figure 4 The optical combiner 231 in can be similar to Figure 2 The optical combiner 231 in FIG. 1 includes an incoming coupler optical device 231a and an outgoing coupler optical device 231b, such that the optical combiner 231 is a waveguide combiner that redirects the display light toward the user's eyes. In addition, the optical combiner 232 can be similar to the reference Figure 3 The optical combiner 231 described above; the incoming coupler optical device 232a can be similar to the reference Figure 3 The incoming coupler optics 231a described above; and the outgoing coupler optics 232b may be similar to those of reference Figure 3 Outgoing coupler optics 231b are depicted. Thus, optical combiner 232 may be a waveguide combiner that redirects the display light toward the user's other eye.

[0067] Optionally, in each WHUD discussed herein, each of the first arm 210 and the second arm 220 may carry any one of a corresponding processor, a corresponding non-transitory processor-readable medium, and a corresponding power supply circuit.

[0068] In a system having multiple light engine components and / or multiple optical combiners (such as Figure 4 In an embodiment of a WHUD 400 shown in FIG. 4 , the WHUD may include a common processor, a common non-transitory processor-readable storage medium, and a common power supply circuit shared by each light engine component.

[0069] Discussed below Figure 5-14 Several possible implementations of optical combiners are described, any of which may be implemented in the WHUDS discussed herein. For example, any of the optical combiners 231 or 232 discussed above may correspond to the optical combiners 231 and 232 described below. Figure 5-14 Any optical combiner discussed. Figure 5-14 Each of the optical combiners shown in the drawings is shaped like a lens to be inserted into a pair of glasses, but any optical combiner can have any suitable shape. For example, any optical combiner can be mask-shaped to fit a head-mounted display, such as a helmet or headpiece. In addition, Figure 5-14 Each of the 2000 and 2001 optical combiners shows a single optical combiner, which, when implemented in a pair of glasses, would produce a display visible to one eye of the user. However, a pair of glasses or any other WHUD may include two of the described optical combiners to produce a binocular display, similar to Figure 4 Alternatively, in some embodiments, a single optical combiner may span in front of both eyes of the user, such as in a mask-type display.

[0070] In addition, the following Figure 5-14Each of the related descriptions describes a different "optical device", including, for example, "incoming coupler optics", "outgoing coupler optics", "expander optics", "recycling optics", and "homogenizing optics". These optical devices are generally used to redirect light in the manner detailed below, and any of these optical devices can include an optical grating, such as a surface relief grating or an optical hologram. An optical hologram can be considered to be a type of optical grating, namely a holographic grating. In addition, throughout the discussion in this article, reference is made to the "efficiency" of a given optical device. This can refer to the proportion of light that is redirected to travel in a desired direction. For example, in the case of an optical grating, "efficiency" can refer to the diffraction efficiency, which describes the proportion of light that is redirected by the optical grating to travel in a particular order of the optical grating. In the case of a surface relief grating, the efficiency can be controlled by controlling, for example, the filling factor or the shape of the ridges and grooves in a given grating. In the case of a holographic grating, the efficiency is controlled by controlling, for example, the refractive index modulation of the holographic grating.

[0071] also, Figure 5-14 Each of the diagrams in FIG. 1 shows light traveling in a different direction. In general, the directional arrows indicate the direction of travel of the light. The circles with an "X" indicate the direction of travel into the page. The circles with a dot indicate the direction of travel out of the page. The empty circles indicate the redirection of display light within the volume of the optical combiner. In addition, Figure 5-14 Display light traveling within the volume of the optical combiner is shown with lateral arrows extending across a distance on the page; however, display light traveling within the volume of the optical combiner may also travel slightly into and out of the page as the display light reflects back and forth between surfaces of the optical combiner.

[0072] Reference below Figure 5-14 In the discussed embodiments, as display light travels through the volume of the optical combiner, the display light will reflect back and forth between opposing surfaces of the optical combiner. Each optical device, including the incoming coupler optics, the outgoing coupler optics, the recycling optics, the expander optics, and / or the homogenizing optics, can be positioned within the optical combiner or at any surface of the optical combiner. When light traveling in the volume of the optical combiner impinges on a given optical device, the impinged optical device will redirect at least a portion of the impinging light. This principle is described in detail in detail in the accompanying drawings. Figure 2 , Figure 3 and Figure 4 , where light is shown traveling through the volume of optical combiner 231 or optical combiner 232, impinging on outgoing coupler optics 231b or outgoing coupler optics 231a, and being redirected to exit from the volume of optical combiner 231 or optical combiner 232. Figure 2 , Figure 3and Figure 4 Transmissive optics are shown, where display light impinges on a given optic and is redirected as the display light passes through the given optic. However, any of the embodiments discussed herein may use reflective optics, where display light impinges on a given optic and is reflected in a desired direction. Furthermore, a combination of reflective and transmissive optics may be implemented in a single optical combiner. Furthermore, any optic in a given optical combiner may be positioned at any boundary of the optical combiner or within the volume of the optical combiner, and any optical combiner may include any combination in which different optics are positioned at different boundaries or at different locations within the volume of the optical combiner.

[0073] Below Figure 5-14 In the discussion of, reference is made to "regions" that contain certain "optics". Examples include: an incoming coupler region that includes an incoming coupler optic, an outgoing coupler region that includes an outgoing coupler optic, a recycling region that includes a recycling optic, an expander region that includes an expander optic, and a homogenizing region that includes a homogenizing optic. The difference between a "region" and an "optic" is that a "region" generally refers to the area or volume of the optical combiner where the "optic" is located, while an "optic" refers to the physical component or feature that redirects light. Orthogonal regions of an optic may define orthogonal regions of the region. Display light may pass through a "region" without having to pass through a corresponding "optic" located in the region. As an example, an optical device may be an optical grating at a boundary of an optical combiner. Display light may travel in the volume of the optical combiner and may impinge on the optic, but a portion of the display light may not be redirected by the optic to exit from the volume of the optical combiner. The portion of the display light may exit from the "region", thereby passing through the region without "passing through" the optic itself.

[0074] Figure 5 is an orthogonal view of the optical combiner 500. The optical combiner 500 includes an incoming coupler region including an incoming coupler optic 510, an outgoing coupler region including an outgoing coupler optic 520, and a recycling region including a recycling optic 530. The incoming coupler optic 510 receives display light 501 from outside the optical combiner 500, such as display light output by a light engine. The incoming coupler optic 510 redirects the display light 501 to travel in the volume of the optical combiner 500, as shown by display light 511. The incoming coupler optic 510 can guide the display light 511 to travel toward the outgoing coupler optic 520 in the outgoing coupler region.

[0075] exist Figure 5, display light 511 traveling in the volume of the optical combiner 500 enters the outgoing coupler region and impinges on the outgoing coupler optics 520 at point 521. At least a portion of the display light 511 will be redirected by the outgoing coupler optics 520 to exit from the volume of the optical combiner 520. However, the outgoing coupler optics 520 may not be 100% efficient, meaning that not all of the light impinging on the outgoing coupler optics 520 will be redirected to exit from the volume of the optical combiner 500. Alternatively, a portion of the display light 511 will continue to travel in the volume of the optical combiner 500 through the outgoing coupler region, as shown by display light 512. A similar effect occurs at point 522, where a portion of the display light 512 is redirected by the outgoing coupler optics 520 to exit from the volume of the optical combiner 500, and a portion of the display light 512 is not redirected to exit from the volume of the optical combiner 500, but instead continues to travel in the volume of the optical combiner 500 as display light 513. A similar effect occurs again at point 523, where a portion of the display light 513 is redirected by the outgoing coupler optics 520 to exit from the volume of the optical combiner 500, and a portion of the display light 513 is not redirected to exit from the volume of the optical combiner 500, but instead continues to travel in the volume of the optical combiner 500 as display light 514.

[0076] although Figure 5 Three points 521, 522, and 523 are shown where display light is redirected to exit from the volume of the optical combiner 500, but in practice the optical combiner 500 can be designed to have fewer or more points at which display light is redirected to exit from the volume of the optical combiner 500. For example, the optical combiner 500 can be made thinner, which will cause light to reflect more frequently between surfaces of the optical combiner 500, thereby increasing the points at which display light impinges on the outgoing coupler optics 520 and is redirected to exit from the optical combiner 500. As another example, the outgoing coupler optics 520 can be made to cover a larger area, which will also increase the number of points at which display light will impinge on the outgoing coupler optics 520 and be redirected to exit from the volume of the optical combiner 500. It may be preferable to have many points at which display light is redirected to exit from the volume of the optical combiner 500, because each point at which light is redirected to exit from the volume of the optical combiner 500 will correspond to an "exit pupil," i.e., a point from which light originates to form a display visible to a user. More exit pupils on a display result in a larger eye zone, thereby improving the visibility of the display. In general, throughout this disclosure, each point at which display light is redirected to exit from the volume of the optical combiner in the user's field of view may correspond to an exit pupil.

[0077] Furthermore, it may be desirable for the outgoing coupler optics 520 to have a relatively low efficiency so that a meaningful amount of light can be redirected to exit from the volume of the optical combiner 500 at multiple points. Figure 5 , display light 511 from an outgoing coupler is redirected to exit from the volume of the outgoing coupler at three sequential points 521, 522, and 523. If the efficiency of the outgoing coupler optics is very high, this will result in very noticeable differences in the brightness of the light that is redirected to exit from the volume of the optical combiner at each point. For example, if the outgoing coupler optics 520 are 95% efficient, this means that 95% of the display light 511 will be redirected to exit from the volume of the optical combiner at point 521, and the display light 512 that continues to travel in the volume of the optical combiner will include 5% of the display light 511. At point 522, 95% of the display light 512 will be redirected to exit from the volume of the optical combiner 500. Since the display light 512 only accounts for 5% of the display light 511, this means that the amount of display light 511 that exits from the volume of the optical combiner at point 522 is 95% of 5%, or 4.75%. That is, in this example, 95% of the display light 511 will exit the volume of the optical combiner 500 at point 521, while only 4.75% of the display light 511 will exit the volume of the optical combiner 500 at the subsequent point 522. By the same token, only 0.2375% of the display light 511 will exit the volume of the optical combiner 520 at the third point 523. Obviously, the amount of display light that exits the volume of the optical combiner 500 at each point is very different, so the resulting display will not be very uniform.

[0078] In order to provide a more uniform display, the efficiency of the outgoing coupler optics 520 can be designed to be relatively low. As an example, if the efficiency of the outgoing coupler optics 520 is 5%, then 5% of the display light 511 will be redirected to exit from the volume of the optical combiner 500 at point 521, 4.75% of the display light 511 will be redirected to exit from the volume of the optical combiner 500 at point 522, and 4.5125% of the display light 511 will be redirected to exit from the volume of the optical combiner 500 at point 523. Obviously, the resulting display will be more uniform. However, due to this lower efficiency, more of the display light traveling in the volume of the optical combiner 511 will pass through the outgoing coupler region without being redirected to exit from the volume of the optical combiner 500, as shown in FIG. Figure 55. In an example where the efficiency of the outgoing coupler optics 520 is 5%, the display light 514 that passes through the outgoing coupler region without being redirected to exit from the volume of the optical combiner will contain 85.7375% of the display light 511. That is, if there were no light recycling features, 85.7375% of the display light directed toward the outgoing coupler region would be wasted. This is a significant problem for several reasons. First, it means that a large amount of power is wasted, which is not ideal for wearable devices where battery size and thus available power are very limited. Second, a more powerful light source is required to produce the necessary amount of light, which may require a larger light source and associated drive circuitry, which is also not ideal for wearable devices that need to reduce size and weight. Third, implementing a more powerful light source may raise concerns about total output power and user eye safety.

[0079] Those skilled in the art will appreciate that the efficiencies and percentages discussed above and throughout this application are merely exemplary, and that the efficiency of each optical device may be appropriately selected based on a given application. In addition, each optical device in a given optical combiner may have the same efficiency, but each optical device in a given optical combiner may also have different efficiencies.

[0080] The present invention solves the above problems by providing at least one recycling optic to redirect otherwise wasted display light toward the outgoing coupler region so that the wasted display light can still be used to form a visible display. Figure 5 In the exemplary optical combiner 500 of , a recycling optic 530 is provided that receives display light 514 that passes through the outgoing coupler region without being redirected to exit from the volume of the optical combiner 500. Generally, the outgoing coupler optic 520 is positioned laterally between the incoming coupler optic 510 and the recycling optic 530. The recycling optic 530 may be, for example, an optical grating. Such a recycling optic 530 may have a period that is half the period of the outgoing coupler optic 520. As an example, the outgoing coupler optic 520 may be a one-dimensional optical grating, and the recycling optic 530 may be another one-dimensional optical grating having a frequency that is twice that of the outgoing coupler optic 520. In the case of a surface relief grating, this means that the frequency of the grooves or ridges of the recycling optic 530 will be twice the frequency of the grooves or ridges of the outgoing coupler optic 520. In the case of a holographic grating, this may mean that the refractive index modulation frequency of the recycling optics 530 may be twice the refractive index modulation frequency of the outgoing coupler optics 520. Thus, the display light 514 impinging on the recycling optics 530 may be redirected to travel in the volume of the optical combiner 500 back toward the outgoing coupler region.

[0081] exist Figure 5 In the example of , display light 514 strikes recycling optics 530 at point 531, which redirects at least a portion of display light 514 back toward the outgoing coupler region as display light 532. Preferably, recycling optics 530 will have a relatively high efficiency to redirect as much display light as possible back toward the outgoing coupler region. However, a completely efficient recycling optic may not be possible. Figure 5 In the example of FIG. 5 , display light 515 is display light that strikes recycling optics 530 at point 531 but is not redirected back toward the outgoing coupler region. Instead, display light 515 continues to travel through the volume of optical combiner 500 away from the outgoing coupler region. To maximize the amount of light that is redirected back toward the outgoing coupler region, recycling optics 530 can cover a larger area so that display light 515 will strike recycling optics 530 again at point 533. A portion of display light 515 will be redirected back toward the outgoing coupler region by recycling optics 530 as display light 534, and a portion of display light 515 will continue to travel through the volume of optical combiner 500 away from the outgoing coupler region, as shown by display light 516. Similarly, display light 516 may impinge on recycling optics 530 at point 535, and a portion of display light 516 will be redirected back toward the outgoing coupler region, as shown by display light 536, and a portion of display light 516 will continue to travel through the volume of optical combiner 500 away from the outgoing coupler region, as shown by display light 517. Display light 517 will still be wasted light, but will contain less light than display light 514. Thus, including recycling optics 530 in optical combiner 500 will reduce the amount of wasted display light.

[0082] Figure 5 The display light is shown impinging on the recycling optics 530 at three points 531, 533, and 535. However, the optical combiner 500 and the recycling optics 530 can be designed so that the display light will impinge on the recycling optics 530 fewer or more times. For example, the recycling optics 530 can be small so that display light traveling in the volume of the optical combiner 500 impinges on the recycling optics 530 only once. As another example, the recycling optics 530 can occupy a large area, and / or the optical combiner 500 can be made very thin so that display light traveling through the volume of the optical combiner 500 will impinge on the recycling grating 530 more than three times.

[0083] The display light 532, 534, and 536 that is redirected back toward the exit coupler region will again illuminate the exit coupler optics 520. Thus, portions of the display light 532, 534, and 536 can be redirected by the exit coupler optics 520 to exit from the volume of the optical combiner 500, which increases the amount of display light that forms a display viewable by a user. Figure 5 Display light 532, 534, and 536 are shown striking the exit coupler optics 520 at the same points 521, 522, and 523 as described above, thereby providing greater brightness for the corresponding exit pupils. However, it is also possible to redirect the display light back toward the exit coupler region to strike different points of the exit coupler optics 520, so that the redirected light will be redirected to exit from the volume of the optical combiner 500 at different points, thereby creating additional exit pupils. Figure 6 , Figure 8 , Fig. 9 and Fig.10 Let’s discuss this concept in more detail.

[0084] Furthermore, each time display light 532, 534, and 536 strikes the exit coupler optics 520, a portion of the display light will be redirected to exit from the volume of the optical combiner 500. Thus, for each point at which a portion of the display light that is redirected back toward the exit coupler region strikes the exit coupler optics 520, the exit coupler optics 520 redirects less of the display light to exit from the volume of the optical combiner 500 than at the previous strike point. Figure 5 In the example of FIG. 5 , less display light 532, 534, and 536 will be redirected to exit from the volume of the optical combiner 500 at point 522 than at point 523. Similarly, at point 521, less display light 532, 534, and 536 will be redirected to exit from the volume of the optical combiner 500 than at point 522. This is similar to the reasons discussed above regarding the efficiency of the outgoing coupler optics 520 when the display light first passes through the outgoing coupler region. Notably, the reduction in display light redirected to exit from the volume of the optical combiner 500 at each point from the recycling optics 530 will be in the opposite direction as compared to the display light first passed from the incoming coupler optics 510 through the outgoing coupler region. Thus, the light redirected back toward the outgoing coupler region by the recycling optics 530 will help to offset the non-uniformity of the light exiting from the volume of the optical combiner 500.

[0085] Figure 5 The recycling optical device 530 in FIG. 5 is shown as being immediately adjacent to the outgoing coupler optical device 520. However, the recycling optical device 530 may also be separated from the outgoing coupler optical device by a gap, as will be described later with reference to FIG. Figure 8 As another example, the recycling optics 530 can be implemented as a secondary optical function of the outgoing coupler optics 520, located in a region of the outgoing coupler optics 520 that is proximate to where display light would exit from the outgoing coupler region without being redirected to exit from the volume of the optical combiner 500.

[0086] Recycling optics can be implemented in a variety of ways, as discussed below. Figure 6-12 A few examples are shown in .

[0087] Figure 6 is an orthogonal view of optical combiner 600. Optical combiner 600 may be similar in at least some respects to Figure 5 For example, the optical combiner 600 may include an incoming coupler region including an incoming coupler optical device 510 and an outgoing coupler region including an outgoing coupler optical device 520. Figure 5 The description of the components in the Figure 6 Parts with similar numbers in .

[0088] and Figure 5 Like the optical combiner 500, Figure 6 The incoming coupler optics 510 of the optical combiner 600 in FIG. 5 can receive display light 501 from outside the volume of the optical combiner, such as from a light engine. The display light 501 can be redirected by the incoming coupler optics 510 to travel in the volume of the optical combiner 600. A portion of the display light 501 that is redirected to travel in the volume of the optical combiner 600 can be redirected by the incoming coupler optics 510 to travel toward an outgoing coupler region including the outgoing coupler optics 520, as shown by display light 511, similar to the reference 5B. Figure 5 Each time the display light 511 strikes the outgoing coupler optics 520, the outgoing coupler optics 520 may redirect a portion of the display light 511 to exit from the volume of the optical combiner 600, similar to the reference Figure 5 as described.

[0089] Figure 6 The optical combiner 600 and Figure 5 One difference between the optical combiner 500 in FIG. 1 and FIG. 2 is that Figure 66, the input coupler optics 510 directs a portion of the display light 501 to travel in the volume of the optical combiner 600 away from the outgoing coupler region, as shown by display light 611. This effect may occur due to the structure of the input coupler optics 510. As an example, if the coupler optics 510 is a diffraction grating, the display light impinging thereon may be directed to travel in multiple diffraction orders, which may include the display light being directed to travel in multiple directions in the volume of the optical combiner. In the absence of any recycling optics, the display light 611 may not be redirected to exit from the volume of the optical combiner 600 as display light visible to a user, and thus the display light 611 may be wasted.

[0090] To solve this problem, Figure 6 The optical combiner 600 in FIG. 5 includes a recycling region including a recycling optic 630 positioned adjacent to or near the incoming coupler optic 510. Figure 6 In the example of FIG. 5 , the recycling optics 630 are positioned along both sides of the incoming coupler optics 510, but in practice, the recycling optics 630 can be larger or smaller and can cover an area more or less surrounding the incoming coupler optics 510. Generally, the incoming coupler optics 510 are positioned laterally between the recycling optics 630 and the outgoing coupler optics 520. In addition, the recycling optics 630 are positioned at the Figure 6 630 is shown in close proximity to the incoming coupler optics 510, but the recycling optics 630 may also be separated by a gap from the incoming coupler optics 510. As another example, the recycling optics 630 may be implemented as a secondary optical function of the incoming coupler optics 510, positioned at an area of ​​the incoming coupler optics 510 that is close to where the display light 611 would otherwise exit from the incoming coupler area without being redirected toward the outgoing coupler area.

[0091] Figure 6The recycling region in receives display light 611 traveling in the volume of the optical combiner 600. The display light 611 can impinge on the recycling optics 630 at point 631, at which point the recycling optics 630 redirects at least a portion of the display light 611 toward the outgoing coupler region, as shown by display light 632. If the efficiency of the recycling optics 630 is 100%, then all of the display light 611 can be redirected toward the outgoing coupler region as display light 632. However, the efficiency of the recycling optics 630 may be less than 100%, so a portion of the display light 611 can pass past point 631 without being redirected by the recycling optics 630 toward the outgoing coupler region. To address this issue, the recycling optics 630 can cover a larger area so that a portion of the display light 611 that passes past point 631 can impinge on the recycling optics 630 more times, resulting in additional portions of the display light 611 being redirected toward the outgoing coupler region, similar to Figure 5 Recycling optics 530 in.

[0092] Display light 632 may travel through the volume of the optical combiner 600 toward an outgoing coupler region including the outgoing coupler optics 520. Display light 632 may impinge on the outgoing coupler optics 520 at point 621, at which the outgoing coupler optics 520 redirects a portion of the display light 632 to exit from the volume of the optical combiner, but may also allow a portion of the display light 632 to continue to travel in the volume of the optical combiner 600, as shown by display light 633. Similarly, display light 633 may impinge on the outgoing coupler optics 520 at point 622, at which the outgoing coupler optics 520 redirects a portion of the display light 633 to exit from the volume of the optical combiner, but may also allow a portion of the display light 633 to continue to travel in the volume of the optical combiner 600, as shown by display light 634. Similarly, display light 634 can impinge on the outgoing coupler optics 520 at point 623, at which point the outgoing coupler optics 520 redirects a portion of the display light 634 to exit from the volume of the optical combiner, but can also allow a portion of the display light 634 to continue traveling in the volume of the optical combiner 600, as shown by display light 635. In summary, similar to reference Figure 5 As described, display light 511 can be redirected to exit from the volume of the optical combiner at the point where display light 511 impinges on the outgoing coupler optics 520, and display light 632 can also be redirected to exit from the volume of the optical combiner 600 at the point where display light 632 impinges on the outgoing coupler optics 520. In addition, Figure 6In the illustrated embodiment, portions of both display light 511 and display light 632 can be redirected by the outgoing coupler optics 520 to exit from the volume of the optical combiner 600, which results in a greater amount of light being redirected to exit from the volume of the optical combiner 600 in the outgoing coupler region. This, in turn, means that more of the display light can be seen by the user, which can provide a brighter and / or more energy efficient display.

[0093] With reference Figure 5 Similar to what is discussed, Figure 6 Three points 621, 622, and 623 are shown at which display light is redirected to exit from the volume of the optical combiner 500, but in practice the optical combiner 600 may be designed to display fewer or more points at which light is redirected to exit from the volume of the optical combiner 600. Exemplary factors that may be modified to control the number of bounces may be the thickness of the optical combiner 600, or the area of ​​the outgoing coupler optics 520.

[0094] The incoming coupler optics 510, outgoing coupler optics 520, and recycling optics 630 can be positioned and oriented so that the points 621, 622, and 623 where the display light 632, 633, and 634 impinge on the outgoing coupler optics 520 coincide with the point where the display light 511 impinges on the outgoing coupler optics 520. This can result in a bright exit pupil, similar to Figure 5 However, Figure 6 The embodiment shown in shows points 621, 622, and 623 at different locations of the point at which the display light 511 impinges on the outgoing coupler optics 520. This can be advantageous by providing more exit pupils across the optical combiner 600, which can improve the eye zone of the display. This can be caused by the relative positioning and orientation of the incoming coupler optics 510, the outgoing coupler optics 520, and the recycling optics 630.

[0095] Figure 6 The optical combiner 600 and Figure 5 Another difference between the optical combiner 500 is Figure 6 Not shown is the recycling optics that redirects display light that has passed through the outgoing coupler region back toward the outgoing coupler region, similar to Figure 5 The recycled optical device 530 in the Figure 6 Such recycling optics are shown in FIG, but it is within the scope of the present disclosure that any of the recycling optics described herein may be implemented together in a single optical combiner suitable for a given application. Figure 7 This concept is shown in .

[0096] Figure 7is an orthogonal view of an optical combiner 700, which may be similar in some respects to Figure 5 The optical combiner 500 and Figure 6 The optical combiner 600 in FIG. Figure 5 and Figure 6 The description of the components in the Figure 7 Similar named components in . Figure 7 An optical combiner 700 is shown, which may include an incoming coupler optical device 510, an outgoing coupler optical device 520, a recycling optical device 530, and a recycling optical device 630. The optical combiner 700 may provide higher power efficiency and / or display brightness than the optical combiner 500 or the optical combiner 600 by including a plurality of recycling optical devices. In particular, similar to Figure 6 The recycling optics 630 can redirect display light that travels through the volume of the optical combiner 700 away from the outgoing coupler region to travel toward the outgoing coupler region. In addition, the recycling optics 530 can redirect display light that travels through the outgoing coupler region in the volume of the optical combiner 700 without being redirected to exit from the volume of the optical combiner 700 back toward the outgoing coupler region, similar to Figure 5 Thus, optical combiner 700 can achieve display light recycling of both optical combiner 500 and optical combiner 600.

[0097] Figure 8 is an orthogonal view of an optical combiner 800, which may be similar in some respects to Figure 5 The optical combiner 500, Figure 6 The optical combiner 600 and Figure 7 The optical combiner 700 in FIG. Figure 5 , Figure 6 and Figure 7 The description of the components in the Figure 8 Similar named components in .

[0098] Figure 8 An optical combiner 800 is shown that includes an incoming coupler region including an incoming coupler optic 810 , an expander region including an expander optic 820 , an outgoing coupler region including an outgoing coupler optic 830 , and a recycling region including a recycling optic 840 .

[0099] The incoming coupler optics 810 will receive the display light 801 from outside the volume of the optical combiner 800 and will redirect the display light 801 to travel within the volume of the optical combiner 800, as shown by display light 811. The display light 811 will be received by the expander optics 820. The expander optics 820 can redirect the display light 811 to travel as multiple spatially separated portions of the display light so that the display light will cover a larger area and create more exit pupils in the outgoing coupler region. Figure 8 , display light 811 impinges on expander optics 820 at point 821, and a portion of display light 811 is redirected to travel in the volume of the optical combiner 800 toward the outgoing coupler region, as shown by display light 822. However, expander optics 820 may not be 100% efficient, such that a portion of display light 811 continues to travel in the volume of the optical combiner 800 without being redirected toward the outgoing coupler region, as shown by display light 823. Display light 823 may impinge on expander optics 820 at point 824, and expander optics 820 redirects a portion of display light 823 to travel in the volume of the optical combiner 800 toward the outgoing coupler region, as shown by display light 825. A portion of display light 823 may continue to travel through the volume of the optical combiner 800 without being redirected toward the outgoing coupler region, as shown by display light 826. Display light 826 may impinge on expander optics 820 at point 827, and expander optics 820 redirects at least a portion of display light 826 to travel within the volume of optical combiner 800 toward the outgoing coupler region, as shown by display light 828. A portion of display light 826 may continue to travel through the volume of optical combiner 800 without being redirected toward the outgoing coupler region, as shown by display light 829. In summary, Figure 8 The expander optical device 820 receives the display light 811 and produces three spatially separated portions of display light 822, 825 and 828, which pass through the space of the optical combiner 800 toward the outgoing coupler region. In practice, fewer or more spatially separated light portions can be produced. This can be achieved, for example, by adjusting the thickness of the optical combiner 800 so that the display light 811 is reflected more or less times between the surfaces of the optical combiner 800 in the expander region. As another example, the expander optical device 820 can cover a larger or smaller area so that the display light 811 is reflected more or less times in the expander region.

[0100] Display light 822, display light 825, and display light 828 can each travel within the volume of optical combiner 800 toward an outgoing coupler region including outgoing coupler optics 830. The following discussion details the optical path of display light 822; display light 825 and display light 828 can follow similar optical paths, spatially separated from the optical path of display light 822, such as Figure 8 However, the specific optical paths of display light 825 and display light 828 are not marked with reference numbers to avoid confusion.

[0101] The display light 822 may impinge on the outgoing coupler optics 830 at point 831, at which the outgoing coupler optics 830 may redirect a portion of the display light 822 to exit from the volume of the optical combiner 800. Another portion of the display light 822 may continue to travel through the volume of the optical combiner 800, as shown by display light 832. The display light 832 may impinge on the outgoing coupler optics 830 at point 833, at which the outgoing coupler optics 830 may redirect a portion of the display light 832 to exit from the volume of the optical combiner 800. Another portion of the display light 832 may continue to travel through the volume of the optical combiner 800, as shown by display light 834. The display light 834 may impinge on the outgoing coupler optics 830 at point 835, at which the outgoing coupler optics 830 may redirect a portion of the display light 834 to exit from the volume of the optical combiner 800. Another portion of display light 834 may continue to travel through the volume of optical combiner 800 , as shown by display light 836 .

[0102] Similar to About Figure 5 , Figure 6 and Figure 7820, the outgoing coupler optics 830 can have a relatively low efficiency in order to achieve a more uniform exit pupil brightness. Therefore, without any recycling optics, the portion of the display light 836 that passes through the outgoing coupler region without being redirected to exit from the volume of the optical combiner can be significant and effectively wasted. To address this issue, the optical combiner 800 can include a recycling region that includes recycling optics 840 that can receive the display light 836. Generally, the outgoing coupler optics 830 are positioned laterally between the recycling optics 840 and the expander optics 820 and the incoming coupler optics 810. The display light 836 can impinge on the recycling region 840 at a point 841, at which point at least a portion of the display light 836 can be redirected to travel in the volume of the optical combiner 800 back toward the outgoing coupler region, as shown by display light 842. If the recycling optics 840 were 100% efficient, all of the display light 836 could be redirected back toward the outgoing coupler region after impinging on the recycling optics 840 at point 841. However, the recycling optics 840 may not be 100% efficient, and thus at least a portion of the display light 836 may continue to travel in the volume of the optical combiner 800 away from the outgoing coupler region. Figure 8 The size of recycling optic 840 is shown so that display light 836 impinges on recycling optic 840 at only one point 841, but display light 836 may impinge on recycling optic 840 many more times, similar to Figure 5 . This can be achieved, for example, by making the recycling optics 840 cover a larger area and / or by making the optical combiner 800 thinner. As a result, at successive points where the display light 836 impinges on the recycling optics 840, a larger proportion of the display light 836 can be redirected to travel in the volume of the optical combiner 800 back toward the outgoing coupler region.

[0103] At point 843, display light 842 traveling in the volume of the optical combiner 800 back from the recycling optics 840 toward the outgoing coupler region can impinge on the outgoing coupler optics 830. A portion of the display light 842 can be redirected by the outgoing coupler optics 830 to exit from the volume of the optical combiner 800, while a portion of the display light 842 can continue to travel in the volume of the optical combiner 800, as shown by display light 844. Display light 844 can impinge on the outgoing coupler optics 830 at point 845, at which a portion of the display light 844 can be redirected by the outgoing coupler optics 830 to exit from the volume of the optical combiner 800, while a portion of the display light 844 can continue to propagate in the volume of the optical combiner 800, as shown by display light 846. The display light 846 may impinge on the exit coupler optics 830 at point 847 , at which point at least a portion of the display light 846 may be redirected by the exit coupler optics 830 to exit from the volume of the optical combiner 800 .

[0104] In summary, recycling optics 840 can receive display light that passes through the outgoing coupler region without being redirected to exit from the volume of optical combiner 800 (display light that would otherwise be wasted), and redirect the received display light back toward the outgoing coupler region, so that at least some of the display light that is redirected back toward the outgoing coupler region can be redirected to exit from the volume of optical combiner 800 as visible light that forms a display. Thus, power efficiency and / or brightness can be improved. In addition, the light that is redirected back from recycling optics 840 toward the outgoing coupler region travels in the opposite direction, so that the amount of display light that is redirected to exit from the volume of optical combiner 800 will be greater at point 843 than at point 845, and will be greater at point 845 than at point 847. This is in contrast to the display light 822 that travels from the expander optics 820 into the outgoing coupler region, such that the amount of display light that is redirected to exit from the volume of the optical combiner 800 will be greater at point 831 than at point 833, and will be greater at point 833 than at point 835. Thus, the display light redirected toward the outgoing coupler region by the recycling optics 840 will help make the overall distribution of the display light exiting from the volume of the optical combiner 800 more uniform.

[0105] exist Figure 8In the illustrated embodiment, each of points 831, 833, 835, 843, 845, and 847 are spatially separated, which results in a greater number of exit pupils for the display, thereby providing a larger eye zone. However, the incoming coupler optics 810, expander optics 820, outgoing coupler optics 830, and recycling optics 840 can be positioned and oriented so that certain points overlap. For example, point 831 can overlap with point 847, point 833 can overlap with point 845, and point 835 can overlap with point 843. This will result in each exit pupil being brighter. In addition, Figure 8 The outgoing coupler optics 830 are shown separated from the recycling optics 840 by a gap "G". The size of the gap G can be adjusted to control the position of the exit pupil for light redirected from the recycling optics 840 back toward the outgoing coupler region. Alternatively, the gap G can be zero, so that the outgoing coupler optics 830 and the recycling optics 840 are in close proximity to each other. As another example, the recycling optics 840 can be implemented as a secondary optical function of the outgoing coupler optics 830, positioned at an area of ​​the outgoing coupler optics 830 that is close to where display light will exit from the outgoing coupler region without being redirected to exit from the volume of the optical combiner 800.

[0106] It is worth noting that in any of the optical combiners described herein, the exact locations of the optics in a given optical combiner may be varied as appropriate for a given application. Figure 8The expander optics 830 are shown as being positioned below the incoming coupler optics 810 and to the right of the outgoing coupler optics 830, but this orientation is not required. As another example, the expander optics 830 can be positioned to the left of the coupler optics 810 and above the outgoing coupler optics 830, and the recycling optics 840 can be positioned below the outgoing coupler optics 830. As yet another example, an optical combiner can include two expander optics, one positioned above the outgoing coupler optics and the other positioned to the right of the outgoing coupler optics to send more spatially separated portions of the display light toward the outgoing coupler region. Such an optical combiner can include additional recycling optics, such as a recycling optic to the left of the outgoing coupler optics and a recycling optic below the outgoing coupler optics, to redirect additional spatially separated portions of the display light that passed through the outgoing coupler region back toward the outgoing coupler region. In addition, the in-coupler optics 810 may also be positioned differently; for example, the in-coupler optics 810 may be positioned anywhere on the top area of ​​the optical combiner or anywhere on any other area of ​​the optical combiner, depending on where the display light from the light engine should be received. Modifications similar to those described above may be implemented in any of the optical combiners described herein.

[0107] Fig. 9 is an orthogonal view of an optical combiner 900, which in some respects may be similar to Figure 8 The optical combiner 800 in FIG. Figure 8 The description of the components in the Fig. 9 For example, optical combiner 900 includes an incoming coupler optic 810, an expander optic 820, and an outgoing coupler optic 830, similar to those in optical combiner 800. In addition, the optical path of the display light from the incoming coupler optic 810 to the expander optic 820, to the outgoing coupler optic 830, to exit from the volume of the optical path optical combiner 900 can be similar to that of reference 1. Figure 8 Those described in the optical combiner 800 in FIG.

[0108] Fig. 9 The optical combiner 900 and Figure 8One difference between the optical combiner 800 in FIG. 9 and FIG. 10 is that the optical combiner 900 includes a recycling region including a recycling optic 940 and a recycling optic 950 positioned adjacent to the expander optic 820. Generally, the expander optic 820 is positioned laterally between the coupler optic 810 and the recycling optic 940, and the expander optic 820 is positioned laterally between the outgoing coupler optic 830 and the recycling optic 950. At point 941, display light 829 that passes through the expander region without being redirected toward the outgoing coupler region can impinge on the recycling optic 940, and at least a portion of the display light 829 will be redirected back toward the expander region, as shown by display light 942. If the efficiency of the recycling optic 940 is 100%, then all of the display light 829 can be redirected back toward the expander region as display light 942 after impinging on the recycling optic 940 at point 941. However, recycling optics 940 may not be 100% effective, and thus at least a portion of display light 829 may continue to travel within the volume of optical combiner 900 without being redirected back toward the expander region. Fig. 9 The recycling optic 940 is shown to be large enough so that the display light 829 impinges on the recycling optic 940 at only one point 941, but the display light 829 may impinge on the recycling optic 940 many more times, similar to Figure 5 This can be achieved, for example, by making the recycling optics 940 cover a larger area, or by making the optical combiner 900 thinner. As a result, at successive points where the display light 829 impinges on the recycling optics 940, a larger proportion of the display light 829 can be redirected to travel within the volume of the optical combiner 900 back toward the expander region.

[0109] Display light 942 redirected by recycling optics 940 back toward the expander region can impinge on expander optics 820 at point 943. Because the propagation direction of display light 942 through the expander region is opposite to the propagation direction of display light 811, expander optics 820 can redirect a portion of display light 942 to travel through the volume of optical combiner 900 away from the outgoing coupler region, as shown by display light 944. This can occur due to the structure of expander optics 820. For example, expander optics 820 can be a diffraction grating that can redirect display light impinging thereon in multiple directions according to different diffraction orders. The propagation direction of the incident light can determine which diffraction orders correspond to possible redirections of the display light, such that display light propagating through the expander region in one direction can be redirected toward the outgoing coupler region, and display light propagating through the expander region in another direction can be redirected away from the outgoing coupler region.

[0110] Another portion of the display light 942 can continue to travel through the volume of the optical combiner 900 without being redirected to travel away from the exit coupler region, as shown by display light 945. The display light 945 can impinge on the expander optics 820 at point 946, where at least a portion of the display light 945 will be redirected to travel away from the exit coupler region in the volume of the optical combiner 900, as shown by display light 947.

[0111] Recycling optics 950 may be positioned adjacent to expander region 820 to receive display light 944 and display light 947. Display light 944 may impinge on recycling optics 950 at point 951, where recycling optics 950 transmits at least a portion of display light 944 toward the outgoing coupler region, as shown by display light 952. Similarly, display light 947 will impinge on recycling optics 950 at point 953, where recycling optics 950 will redirect at least a portion of display light 947 toward the outgoing coupler region, as shown by display light 954. If recycling optics 950 is 100% efficient, all of display light 944 and display light 947 may be redirected toward the outgoing coupler region after impinging on recycling optics 950 at either point 951 or point 953. However, recycling optics 950 may not be 100% efficient, and thus at least a portion of display light 944 and display light 947 may continue to travel within the volume of optical combiner 900 without being redirected toward the outgoing coupler region. Fig. 9 The size of recycling optics 950 is shown such that display light 944 impinges on recycling optics 950 at only one point 951, and display light 947 impinges on recycling optics 950 at only one point 953. Display light 944 and display light 947 may each impinge on recycling optics 950 multiple times, similar to Figure 5 This can be achieved, for example, by making recycling optics 950 cover a larger area or by making optical combiner 900 thinner. As a result, at successive points where display light 944 and display light 947 impinge on recycling optics 950, a greater proportion of display light 944 and display light 947 can be redirected to travel in the volume of optical combiner 900 toward the outgoing coupler region.

[0112] Display light 952 redirected by recycling optics 950 toward the outgoing coupler region may impinge on outgoing coupler optics 830 at point 931 where a portion of display light 952 will be redirected to exit from the volume of optical combiner 900, and a portion of display light 952 will continue to travel in the volume of optical combiner 900, as shown by display light 932. Display light 932 may impinge on outgoing coupler optics 830 at point 933 where a portion of display light 932 will be redirected to exit from the volume of optical combiner 900, and a portion of display light 932 will continue to travel in the volume of optical combiner 900, as shown by display light 934. Display light 934 may impinge on outgoing coupler optics 830 at point 935 where at least a portion of display light 934 will be redirected to exit from the volume of optical combiner 900.

[0113] like Fig. 9 As shown, the optical path of display light 954 through outgoing coupler optics 830 can be similar to the optical path of display light 952 through the above-described outgoing coupler optics 830. However, the optical path of display light 954 through outgoing coupler optics 830 is not labeled with a reference number to reduce confusion.

[0114] like Fig. 9 As can be seen in FIG. 1 , the optical path of display light 952 through the outgoing coupler region including the outgoing coupler optical device 830, and the optical path of display light 954 through the outgoing coupler region including the outgoing coupler optical device 830 can be similar to the optical paths of the spatially separated portions of the display light from the expander optical device 820, as shown in reference Figure 8 As discussed. Fig. 9 , the incoming coupler optics 810, expander optics 820, outgoing coupler optics 830, recycling optics 940, and recycling optics 950 can be positioned and oriented so that the optical paths of display light 952 and display light 954 passing through the outgoing coupler optics 830 are spatially separated from the optical paths of spatially separated portions of the display light from the expander optics 820 to form an additional exit pupil. Alternatively, the incoming coupler optics 810, expander optics 820, outgoing coupler optics 830, recycling optics 940, and recycling optics 950 can be positioned and oriented so that the point at which display light 952 and display light 954 are redirected by the outgoing coupler optics 830 to exit from the volume of the optical combiner 900 coincides with the point at which display light from the expander optics 820 is redirected by the outgoing coupler optics 830 to exit from the volume of the optical combiner 900, thereby providing a brighter exit pupil.

[0115] Similar to the discussion throughout this disclosure, for example, the number of points at which display light impinges on the expander optics 820 and the outgoing coupler optics 830 can be adjusted by making the expander optics 820 and / or the outgoing coupler optics 830 cover a larger area or by adjusting the thickness of the optical combiner 800.

[0116] Recycling optics 940 and recycling optics 950 are Fig. 9 820. However, in some embodiments, recycling optics 940 and / or recycling optics 950 can be spatially separated by a gap from expander optics 820. As another example, recycling optics 940 and / or recycling optics 950 can be implemented as a secondary optical function of expander optics 820, located in a peripheral region of expander optics 820.

[0117] Fig. 9 The optical combiner 900 and Figure 8 Another difference between the optical combiner 800 in FIG. 1 and FIG. 2 is that the optical combiner 900 is not shown as including a recycling optic 840 positioned adjacent to the outgoing coupler optic 830. However, such a recycling optic 840 may be included, as will be described later with reference to FIG. Fig.11 discussed.

[0118] Fig.10 is an orthogonal view of an optical combiner 1000, which may be similar in some respects to Figure 8 The optical combiner 800 and Fig. 9 The optical combiner 900 shown in FIG. Figure 8 and Fig. 9 The description of the components in the Fig.10 For example, optical combiner 1000 includes incoming coupler optics 810, expander optics 820, and outgoing coupler optics 830, similar to those in optical combiner 800 and optical combiner 900. In addition, the optical path of display light from incoming coupler optics 810 to expander optics 820, to outgoing coupler optics 930, to exit from the volume of optical combiner 1000 can be similar to that of reference 1000. Figure 8 Those described for the optical combiner 800 in FIG.

[0119] Fig.10 The optical combiner 1000 and Figure 8One difference between the optical combiner 800 in FIG. 1 and FIG. 2 is that the optical combiner 1000 includes a recycling region including a recycling optic 1040 positioned adjacent to the incoming coupler optic 810. Generally, the incoming coupler optic 810 is positioned laterally between the expander optic 820 and the recycling optic 1040. Similar to the reference Figure 8 As depicted, the incoming coupler optic 810 receives display light 801 from outside the volume of the optical combiner 1000, such as from a light engine. The incoming coupler optic 810 redirects a portion of the display light 801 to travel in the volume of the optical combiner 1000 toward the expander region, as shown by display light 811. The incoming coupler optic 810 also redirects another portion of the display light 801 to travel in the volume of the optical combiner 1000 away from the expander region, as shown by display light 1011. This effect may occur due to the structure of the coupler optic 810. As an example, if the incoming coupler optic 810 is a surface relief grating, the display light impinging on the incoming coupler optic 810 may be directed to travel in multiple directions in the volume of the optical combiner. Without any recycling optics, the display light 1011 may not be redirected to exit from the volume of the optical combiner 1000 as display light visible to a user, and thus the display light 1011 may be wasted.

[0120] Recycling optics 1040 solves this problem. Fig.10 In the example of FIG. 8 , the recycling optics 1040 are positioned along both sides of the incoming coupler optics 810, but in practice, the recycling optics 1040 can be larger or smaller and can cover more or less area around the coupling optics 810. Fig.10 810, but the recycling optic 1040 may also be separated by a gap from the incoming coupler optic 810. As another example, the recycling optic 1040 may be implemented as a secondary optical function of the incoming coupler optic 810, positioned at an area of ​​the incoming coupler optic 810 that is close to where the display light 1011 would exit from the incoming coupler region without being redirected toward the expander region.

[0121] Fig.10The recycling region in the optical combiner 1000 receives display light 1011 traveling in the volume of the optical combiner 1000. The display light 1011 can impinge on the recycling optics 1040 at point 1041, where the recycling optics 1040 redirects at least a portion of the display light 1011 toward the expander region, as shown by display light 1042. If the efficiency of the recycling optics 1040 is 100%, then all of the display light 1011 can be redirected toward the outgoing coupler region as display light 1042. However, the efficiency of the recycling optics 1040 can be less than 100%, and thus a portion of the display light 1011 can pass through point 1041 without being redirected by the recycling optics 1040 toward the expander region. To address this issue, the recycling optics 1040 can cover a larger area, or the optical combiner 1000 can be thinner so that a portion of the display light 1011 passing past point 1041 can impinge on the recycling optics 1040 more times, causing an additional portion of the display light 1011 to be redirected toward the expander area.

[0122] Display light 1042 redirected by recycling optics 1040 toward the expander region will impinge on expander optics 820 at point 1043, where a portion of display light 1042 is redirected toward the outgoing coupler region as display light 1044. Another portion of display light 1042 may continue to travel through the volume of optical combiner 1000 without being redirected toward the outgoing coupler region, as shown by display light 1045. Display light 1045 will impinge on expander optics 820 at point 1046, where at least a portion of display light 1045 is redirected toward the outgoing coupler region as display light 1047.

[0123] Display light 1047 redirected toward the coupler region by the expander optics 820 may impinge on the outgoing coupler optics 830 at point 1031 where a portion of the display light 1047 will be redirected to exit from the volume of the optical combiner 1000, and a portion of the display light 1047 will continue to travel in the volume of the optical combiner 1000, as shown by display light 1032. Display light 1032 may impinge on the outgoing coupler optics 830 at point 1033 where a portion of the display light 1032 will be redirected to exit from the volume of the optical combiner 1000, and a portion of the display light 1032 will continue to travel in the volume of the optical combiner 1000, as shown by display light 1034. Display light 1034 may impinge on the outgoing coupler optics 830 at point 1035 where at least a portion of the display light 1034 will be redirected to exit from the volume of the optical combiner 1000.

[0124] like Fig.10 As can be seen in FIG. 1 , the optical path of display light 1044 through the outgoing coupler region including the outgoing coupler optical device 830 can be similar to the optical path of display light 1047 described above through the outgoing coupler region including the outgoing coupler optical device 830. However, the optical path of display light 1044 through the outgoing coupler region is not labeled with a reference numeral to reduce confusion.

[0125] like Fig.10 As can be seen in FIG. 1 , the optical path of display light 1047 through the outgoing coupler region including the outgoing coupler optical device 830, and the optical path of display light 1044 through the outgoing coupler region can be similar to the optical paths of the spatially separated portions of display light 811 redirected by the expander optical device 820, as shown in reference Figure 8 As discussed. Fig.10 , the incoming coupler optics 810, expander optics 820, outgoing coupler optics 830, and recycling optics 1040 can be positioned and oriented so that the optical paths of display light 1047 and display light 1044 that pass through the outgoing coupler region are spatially separated from the optical paths of the spatially separated portions of display light 811 redirected by the expander optics 820 to form an additional exit pupil. Alternatively, the incoming coupler optics 810, expander optics 820, outgoing coupler optics 830, and recycling optics 1040 can be positioned and oriented so that the point at which display light 1047 and display light 1044 are redirected by the outgoing coupler optics 830 to exit from the volume of the optical combiner 1000 coincides with the point at which the portion of display light 811 redirected by the expander optics 820 is redirected by the outgoing coupler optics 830 to exit from the volume of the optical combiner 1000, thereby providing a brighter exit pupil.

[0126] Similar to the discussion throughout this disclosure, for example, the number of points at which display light impinges on the expander optics 820 and the outgoing coupler optics 830 can be adjusted by making the expander optics 820 and / or the outgoing coupler optics 830 cover a larger area or by adjusting the thickness of the optical combiner 800.

[0127] Fig.10 The optical combiner 1000 and Figure 8 Another difference between the optical combiner 800 in FIG. 1 and FIG. 2 is that the optical combiner 1000 is not shown as including a recycling optic 840 positioned adjacent to the outgoing coupler optic 830. However, such a recycling optic 840 may be included, as described below with reference to FIG. Fig.11 discussed.

[0128] Fig.11is an orthogonal view of an optical combiner 1100, which may be similar in some respects to Figure 8 The optical combiner 800, Fig. 9 The optical combiner 900 and Fig.10 The optical combiner 1000 in FIG. Figure 8 , Fig. 9 and Fig.10 The description of the components in the Fig.11 Similar named components in . Fig.11 An optical combiner 1100 is shown, which may include an incoming coupler optic 810, an expander optic 820, an outgoing coupler optic 830, a recycling optic 840, a recycling optic 940, a recycling optic 950, and a recycling optic 1040. By including a plurality of recycling optics, the optical combiner 1100 may provide higher power and / or display brightness than the optical combiner 800, the optical combiner 900, or the optical combiner 1000. In particular, the recycling optic 840 may redirect display light that travels in the volume of the optical combiner 1100 through an outgoing coupler region including the outgoing coupler optic 830 without being redirected to exit from the volume of the optical combiner 1100 back toward the outgoing coupler region, similar to Figure 8 In addition, recycling optics 940 and recycling optics 950 can redirect display light that travels through the expander region including expander optics 820 in the volume of optical combiner 1100 without being redirected toward the outgoing coupler region to travel toward the outgoing coupler region, similar to Fig. 9 In the embodiment of the present invention, recycling optics 940 and recycling optics 950 are shown in FIG. 1. In addition, recycling optics 1040 can redirect display light that travels through the volume of optical combiner 1100 away from the outgoing coupler region to travel toward the outgoing coupler region, similar to Fig.10 1040 in the recycling region. Thus, optical combiner 1100 can implement the display light recycling of optical combiner 800, optical combiner 900, and optical combiner 1000. In addition, each of recycling optics 840, recycling optics 940, recycling optics 950, and recycling optics 1040 need not be together in a single optical combiner. Instead, any suitable combination of recycling optics can be implemented together as needed for a given application.

[0129] Fig.12 is an orthogonal view of an optical combiner 1200, which may be similar in some respects to Figure 5 The optical combiner 500, Figure 6 The optical combiner 600, Figure 7 The optical combiner 700, Figure 8 The optical combiner 800, Fig. 9 Optical combiner 900, Fig.10 The optical combiner 1000 and Fig.11 The optical combiner 1100 in FIG. Figure 5 , Figure 6 , Figure 7 , Figure 8 , Fig. 9 , Fig.10 and Fig.11 The description of the components in the Fig.12 Similar named components in .

[0130] Fig.12 An optical combiner 1200 is shown, which may include an incoming coupler region including an incoming coupler optic 1210, an outgoing coupler region including an outgoing coupler optic 1220, and a recycling region including a recycling optic 1230. The incoming coupler region 1210 may receive display light 1201 from outside the volume of the optical combiner 1200, and redirect the display light 1201 to travel through the volume of the optical combiner in a direction D1 toward the outgoing coupler region, as shown by display light 1211. The outgoing coupler optic 1220 may be a two-dimensional optical grating, such that the outgoing coupler optic 1220 expands the received display light over a relatively large area, and redirects the display light to exit from the volume of the optical combiner 1200. The outgoing coupler optic 1220 may thereby produce a display having multiple exit pupils. This will be described in more detail below. Generally, the outgoing coupler optics 1220 are positioned laterally between the incoming coupler optics 1210 and the recycling optics 1230 .

[0131] exist Fig.12, the outgoing coupler region can receive display light 1211 that travels through the volume of the optical combiner 1200 in direction D1, and when the display light 1211 impinges on the outgoing coupler optics 1220, the outgoing coupler optics 1220 can redirect the display light 1211 to travel through the volume of the optical combiner 1200 in multiple directions. This can be seen at each empty circle shown in the outgoing coupler optics 1220, where a portion of the light continues to travel in a first direction, while two portions of the light are redirected in other directions. This is numerically labeled point 1221, where a portion of the display light 1211 that has traveled in direction D1 on its way through the outgoing coupler region impinges on the outgoing coupler optics 1220. At point 1221, the outgoing coupler optics 1220 redirects a portion of the display light 1211 to travel through the volume of the optical combiner 1200 in a direction D2 that is different from direction D1, as shown by display light 1222. Additionally, at point 1221, the outgoing coupler optics 1220 redirects another portion of the display light 1211 to travel through the volume of the optical combiner 1200 in a direction D3 that is different from the directions D1 and D2, as shown by display light 1223. At point 1221, another portion of the display light 1211 may continue to travel through the volume of the optical combiner 1200 in the direction D1, as shown by display light 1223. Fig.12 As shown in the display light 1224. Fig.12 In the example shown, direction D2 and direction D3 may be parallel but opposite directions, and direction D1 may be perpendicular to direction D2 and direction D3. However, the outgoing coupler optical device 1220 may be designed to achieve any suitable relationship between the directions. As an example, the outgoing coupler optical device 1220 may include a holographic optical grating with a separate grating function for each light direction.

[0132] In the context of the present invention, the description of display light traveling along a certain direction does not require that the display light travels completely parallel to the specific direction, but rather indicates that the display light travels approximately along the direction. Fig.13 References to display light traveling in directions D1, D2, and D3 may refer to display light traveling within an angular range in the corresponding directions. Examples of acceptable angular ranges may include 30°, 20°, 10°, 5°, 1°, or 0°, but may be any angular range suitable for a given application.

[0133] like Fig.12 As can be seen in FIG, a portion of the light redirected by the outgoing coupler optics 1220 to travel in a direction other than direction D1 can be redirected to exit from the volume of the optical combiner 1200 at the point where the portion of light impinges on the outgoing coupler optics 1220. Fig.121225, wherein display light 1222 traveling in direction D2 through the volume of the optical combiner 1200 impinges on the outgoing coupler optics at point 1225. A portion of the display light 1222 is redirected by the outgoing coupler optics 1220 to exit from the volume of the optical combiner 1200 at point 1225, and a portion of the display light 1222 continues to travel in direction D2 through the volume of the optical combiner 1200, as shown by display light 1226. In addition, display light 1226 impinges on the optical combiner 1200 at point 1227, wherein a portion of the display light 1226 is redirected by the outgoing coupler optics 1220 to exit from the volume of the optical combiner 1200, and a portion of the display light 1226 continues to travel in direction D2 through the volume of the optical combiner 1200, as shown by display light 1228.

[0134] From the above and Fig.12 It will be appreciated that the outgoing coupler optics 1220 is two-dimensional because the outgoing coupler optics 1220 includes multiple optical functions: a function of redirecting light traveling in direction D1 to travel in other directions through the volume of the optical combiner 1200, and at least one additional function of redirecting light traveling in other directions to exit from the volume of the optical combiner. For example, the outgoing coupler optics 1200 may include a surface relief grating, wherein two optical grating functions are superimposed on each other. As another example, the outgoing coupler optics may include a holographic medium in which two holographic grating functions are recorded. Such holographic grating functions may be recorded in the same volume of the holographic medium, or may be recorded in separate holographic volumes that are superimposed on each other.

[0135] The optical combiner 1200 can include recycling optics 1230 that can receive display light that passes through the outgoing coupler region without being redirected to exit from the volume of the optical combiner 1200, and can redirect the received display light back toward the outgoing coupler region. As an example, Fig.12 Display light 1228 is shown traveling through the volume of the optical combiner 1200 in direction D2, exiting from the outgoing coupler region into a recycling region including recycling optics 1230. The display light 1228 may impinge on the recycling optics 1230 at point 1231, wherein the recycling optics 1230 redirects at least a portion of the display light 1228 back toward the outgoing coupler region, as shown by display light 1232. The display light 1232 will thereby travel through the outgoing coupler region, and will at least once more impinge on the outgoing coupler optics 1220, such that at least some of the display light 1232 may be redirected to exit from the volume of the optical combiner 1200 as display light visible to a user, similar to the reference 1230. Figure 5, Figure 6 , Figure 8 , Fig. 9 and Fig.10 This will increase the brightness and / or power efficiency of the display. As another example, Fig.12 Display light 1224 is shown traveling through the volume of the optical combiner 1200 in a first direction, exiting from the outgoing coupler region into a recycling region including recycling optics 1230. The display light 1224 may impinge on the recycling optics 1230 at a point 1233, at which point the recycling optics 1230 redirects at least a portion of the display light 1224 back toward the outgoing coupler region as display light 1234. The display light 1234 will thereby travel through the outgoing coupler region, and will at least once more impinge on the outgoing coupler optics 1220, such that at least some of the display light 1234 may be redirected to travel through the volume of the optical combiner 1200 in other directions, and subsequently be redirected to exit from the volume of the optical combiner 1200 as display light visible to a user, similar to reference 1200. Figure 5 , Figure 6 , Figure 8 , Fig. 9 and Fig.10 This will increase the brightness and / or power efficiency of the display.

[0136] Similar to the reference above Figure 8 , Fig. 9 and Fig.10 As discussed, recycling optics 1230 in Fig.12 1200 is shown as being only large enough so that light that passes through the outgoing coupler area impinges once on the recycling optics 1230. If the recycling optics 1230 are not efficient, the recycling optics 1230 can be made to cover a larger area, or the optical combiner 1200 can be made thinner, for example, so that the display light will impinge on the optical combiner 1200 more than once, thereby increasing the amount of display light that is redirected back toward the outgoing coupler optics 1220.

[0137] Fig.12An optical combiner 1200 is shown including a recycling optic 1230 positioned adjacent to and partially surrounding the outgoing coupler optic 1220. However, the particular boundaries of the recycling optic 1230 may be appropriately selected for a given application. For example, the recycling optic may be positioned adjacent to only one side of the outgoing coupler optic 1220 to reduce the area occupied by the optic. In some embodiments, the recycling optic 1230 may be positioned immediately adjacent to the outgoing coupler optic 1220. In some embodiments, at least a portion of the recycling optic 1230 may be spatially separated from the outgoing coupler optic 1220 by a gap. As another example, the recycling optic 1230 may be implemented as a secondary optical function of the outgoing coupler optic 1220, positioned at an area of ​​the outgoing coupler optic 1220 that is proximate to where display light will exit from the outgoing coupler area without being redirected to exit from the volume of the optical combiner 1200.

[0138] In addition, the optical combiner 1200 may include additional recycling optics to increase brightness and / or power efficiency. For example, the recycling optics may be positioned adjacent to the coupler optics 1210, similar to Figure 6 Recycling optics 630 shown in FIG.

[0139] Fig.13 is an orthogonal view of an optical combiner 1300, which may be similar in some respects to the optical combiner 1200. Figure 5 The optical combiner 500, Figure 6 The optical combiner 600, Figure 7 The optical combiner 700, Figure 8 The optical combiner 800, Fig. 9 Optical combiner 900, Fig.10 Optical combiner 1000, Fig.11 The optical combiner 1100 and Fig.12 The optical combiner 1200 in FIG. Figure 5 , Figure 6 , Figure 7 , Figure 8 , Fig. 9 , Fig.10 , Fig.11 and Fig.12 The description of the components in the Fig.13 Similar named components in .

[0140] Fig.13An optical combiner 1300 is shown that includes an incoming coupler region including an incoming coupler optic 1310, an expander region including an expander optic 1320, a uniformizing region including a uniformizing optic 1330, and an outgoing coupler region including an outgoing coupler optic 1340. Generally, the uniformizing optic 1330 is positioned laterally between the expander optic 1320 and the outgoing coupler optic 1340.

[0141] Fig.13 The incoming coupler optics 1310 in can be similar to that of reference Figure 8 Incoming coupler optics 810 are depicted. Incoming coupler optics 1310 will receive display light 1301 from outside the volume of the optical combiner 1300 and redirect the display light 1301 to travel within the volume of the optical combiner 1300, shown as display light 1311 traveling toward the expander region. Fig.13 The direction D4 in which the display light 1311 travels is shown. In the context of the present invention, the description of the display light traveling along a certain direction does not require that the display light travels completely parallel to the specific direction, but indicates that the display light travels generally along the direction. Fig.13 The display light traveling along direction D4 in the above description may refer to the display light traveling within the angular range of direction D4. Examples of acceptable angular ranges may include 30°, 20°, 10°, 5°, 1°, or 0°, but may be any angular range suitable for a given application. Fig.13 In the example of FIG. 1 , the display light 1311 can travel away from the coupler 1310 in a cone, where the display light 1311 gradually diverges as it moves farther from the incoming coupler 1310 .

[0142] Display light 1311 will be received by an expansion area including expander optics 1320. Expander optics 1320 can redirect display light 1311 as multiple spatially separated portions of display light along Fig.13 The direction D5 shown in FIG. 1 is not parallel to the direction D4 and may be perpendicular to the direction D4, but in FIG. 1 . Fig.13 In the example of , direction D5 is neither parallel to D4 nor perpendicular to D4. Similar to the direction D4 discussed above, in Fig.13 The display light traveling along direction D5 may refer to the display light traveling within the angular range of direction D5. Examples of acceptable angular ranges may include 30°, 20°, 10°, 5°, 1°, or 0°, but may be any angular range suitable for a given application.

[0143] and Fig.13Compared with the directions D4 and D5, Fig.12 There does not need to be a specific relationship between the directions D1, D2, and D3 in . Instead, Fig.13 Directions D4 and D5 in FIG. 1 are numbered in this way to avoid overlapping of reference numerals with D1 , D2 , and D3 .

[0144] exist Fig.13 , display light 1311 impinges on expander optics 1320 at point 1321, and a portion of display light 1311 is redirected to travel in the volume of the optical combiner 1300 in direction D5 toward the homogenizing region, as shown by display light 1322. However, the expander optics may not be 100% efficient, and a portion of display light 1311 may continue to travel in the volume of the optical combiner 1300 in direction D4 without being redirected toward the homogenizing region, as shown by display light 1323. Display light 1323 may impinge on expander optics 1320 at point 1324, and expander optics 1320 redirects a portion of display light 1323 to travel in the volume of the optical combiner 1300 in direction D5 toward the homogenizing region, as shown by display light 1325. Display light 1323 may continue to travel in direction D4 through the volume of the optical combiner 1300 without being redirected toward the homogenizing region, as shown by display light 1326. Display light 1326 can impinge on expander optics 1320 at point 1327, and expander optics 1320 redirects at least a portion of display light 1326 to travel in direction D5 in the volume of optical combiner 1300 toward the homogenization region, as shown by display light 1328. A portion of display light 1326 can continue to travel in direction D4 through the volume of optical combiner 1300 without being redirected toward the homogenization region, as shown by display light 1329. In summary, Fig.13 Expander optics 1320 receives display light 1311 and generates three spatially separated portions of display light 1322, 1325, and 1328 that travel along direction D5 through the volume of optical combiner 1300 toward the homogenization region. In practice, fewer or more spatially separated light portions may be generated, such as by changing the area covered by expander optics 1320, or changing the thickness of optical combiner 1300, so that the display light will impinge on expander optics 1320 more times.

[0145] Regarding the above Figure 5Similarly as discussed, if expander optics 1320 has a relatively high efficiency, the spatially separated portions of the display light will not have very uniform brightness, which will result in a display with non-uniform brightness. For example, if expander optics 1320 has an efficiency of 95%, display light 1322 will include 95% of display light 1311; display light 1325 will include 4.75% of display light 1311; and display light 1328 will include 0.2375% of display light 1311. Obviously, this distribution of display light is not very uniform. This can be solved by designing expander optics 1320 to have a lower efficiency. For example, if expander optics 1320 has an efficiency of 5%, display light 1322 will include 5% of display light 1311; display light 1325 will include 4.75% of display light 1311; and display light 1328 will include 4.5125% of display light 1311. This distribution of display light is more uniform, but 85.7375% of the display light 1311 will pass through the expander region without being redirected toward the outgoing coupler region to produce a visible display. That is, Fig.13 Display light 1329 in will include 85.7375% of display light 1311, which is a significant waste.

[0146] In view of the above, it is desirable that the expander optical device 1320 has high efficiency overall to reduce wasted display light, but still maintain a uniform distribution of light. The present disclosure provides a solution to this problem, such as Fig.13 13. The uniformizing optical device 1330 in FIG. The uniformizing optical device 1330 is used to receive at least one of the spatially separated portions of the display lights 1322, 1325, and 1328, and redistribute the display light from the brighter portion of the display light (such as the display light 1322) to the area where the darker portion of the display light (such as the display light 1328) travels. This is described in detail below.

[0147] Display light 1322 is received by the homogenization region and impinges on uniformizing optics 1330 at point 1331. A sub-portion of display light 1322 is redirected by uniformizing optics 1330 to travel in direction D4, as shown by display light 1331a. Display light 1331a will travel in direction D4 until impinging uniformizing optics 1330 again at point 1333, where a sub-portion of display light 1331a is redirected by uniformizing optics 1330 to travel in direction D5, as shown by 1333b, while another sub-portion of display light 1331a continues to travel in direction D4, as shown by display light 1333a. Display light 1333b is a sub-portion of display light 1322, where display light 1333b has been shifted to be spatially separated from display light 1322. That is, sub-portion 1333b of display light 1322 has been "tapped-off" and shifted to travel in direction D5 in a region where the display light from expander optics 1320 is darker. In this case, sub-portion 1333b travels in a region between display light 1322 and display light 1325.

[0148] Display light 1333a traveling in direction D4 may impinge on uniformizing optics 1330 at point 1335, where a sub-portion of display light 1333a may be redirected to travel in direction D5, as shown by display light 1335b. Fig.13 Display light 1335b in FIG. 1 may represent a combination of display light 1325 from expander optics 1320 and a sub-portion of display light 1333a redirected by uniformizing optics 1330. Display light 1333a is a sub-portion of display light 1322 that has been redirected by uniformizing optics 1330; that is, a sub-portion of display light 1322 is “tapped” by uniformizing optics 1330 and redirected to contribute to the brightness of display light 1325. In summary, a sub-portion of display light 1322 (the brightest display light from expander optics 1320) is redirected to another area (the area where display light 1325 travels) where the display light is darker.

[0149] At point 1335, a sub-portion of display light 1333a may continue to travel in direction D4, as shown by display light 1335a. Additionally, display light 1325 may impinge on uniformizing optics 1330 at point 1335, and a portion of display light 1325 may be redirected to travel in direction D4. Fig.13Display light 1335a in 1334 may represent a combination of a sub-portion of display light 1333a traveling in direction D4 and a sub-portion of display light 1325 traveling in direction D4. Display light 1335a may impinge on uniformizing optics 1330 at point 1337, where a sub-portion of display light 1335a will be redirected to travel in direction D5, as shown by display light 1337b, and a sub-portion of display light 1335a will continue to travel in direction D4, as shown by display light 1337a. Display light 1337a may impinge on uniformizing optics 1330 at point 1338, where at least a portion of display light 1337a may be redirected to travel in direction D5, as shown by display light 1337b. Fig.13 In addition, display light 1338b may represent that a combination of sub-portions of display light 1328 and display light 1337a are redirected to travel in direction D5. In summary, sub-portion 1322 of display light (the brightest display light from expander optical device 1320) and sub-portion 1325 of display light (display light with a medium brightness from expander optical device 1320) are redirected to another area where the display light is darker (display light 1328 is from Fig.13 The dimmest displayed light of the expander optics 1320 shown).

[0150] Fig.13 Three spatially separated portions of display light (display light 1322, display light 1325, and display light 1328) are shown redirected by expander optics 1320 to travel in direction D5. However, any suitable number of spatially separated portions of light may be produced by expander optics 1320, such as by modifying the thickness of optical combiner 1400 and / or modifying the area of ​​expander optics 1320.

[0151] Generally, it is desirable for uniformizing optics 1330 to redirect display light from brighter areas to darker areas while minimizing the amount of light redirected away from the darker areas. Fig.13 In the example of , the brightest display light (display light 1322) will travel through the top of the homogenization region (the region of the homogenization optics 1330 closest to the incoming coupler optics 1310), while the darkest display light (display light 1328) will travel through the bottom of the homogenization region (the region of the homogenization optics 1330 farthest from the coupler optics 1310). Fig.13In the example of , more display light is preferably redirected from the top region of the homogenization region toward the bottom region of the homogenization region. This can be achieved in a variety of ways. For example, the homogenization optics 1330 can be a grating with variable efficiency, and the efficiency of the top region is higher than the efficiency of the bottom region. That is, for a region of the homogenization optics 1330 that is close to the incoming coupler optics 1310, the homogenization optics 1330 can have a first efficiency, and for a region of the homogenization optics 1330 that is far from the incoming coupler optics 1310, the homogenization optics 1330 can have a second efficiency, and the first diffraction efficiency is greater than the second diffraction efficiency.

[0152] As another example, Fig.13 As shown, the width of the uniformizing optical device 1330 along the direction D5 for the top region can be greater than the width of the uniformizing optical device 1330 along the direction D5 for the bottom region. That is, for the region of the uniformizing optical device 1330 close to the incoming coupler grating 1310, the uniformizing optical device 1330 can have a first width in the direction D5, and for the region of the uniformizing optical device 1330 far from the incoming coupler grating 1310, the uniformizing optical device 1330 can have a second width in the direction D5, and the first width is greater than the second width. This can be Fig.13 , where display light 1322 traveling in direction D5 impinges on uniformizing optics 1330 at point 1331, and a sub-portion of display light 1322 that continues traveling in direction D5 (as shown by display light 1331b) impinges on uniformizing optics 1330 at point 1332. That is, display light 1322 impinges on uniformizing optics 1330 twice in direction D5, compared to display light 1328 impinging only once. Impinging on uniformizing optics 1330 more times will result in more display light being redirected toward areas where the display light is darker. In particular, at Fig.13 In the example of FIG. 13 , at point 1332, display light 1331b impinges on uniformizing optical device 1330, wherein a sub-portion of display light 1331b is redirected by uniformizing optical device 1330 to travel in direction D4, as shown by display light 1332a, and a sub-portion of display light 1331b continues to travel in direction D5, as shown by display light 1332b. In other words, a sub-portion of display light 1322 is “tapped” at point 1331, and another sub-portion of display light 1322 is “tapped” at point 1332.

[0153] At point 1334, a sub-portion of display light 1332a is redirected by uniformizing optics 1330 to travel in direction D5, as shown by display light 1334b. Display light 1334b may represent a combination of sub-portions of display light 1332a that are redirected by uniformizing optics 1330 to travel in direction D5 at point 1334, in addition to display light 1333b discussed above. Thus, a sub-portion of display light 1322 may be redirected to travel spatially separated from display light 1322 in direction D5, thereby redirecting display light from a brighter area to a darker area.

[0154] Similarly, at point 1334, a sub-portion of display light 1333b can be redirected by uniformizing optics 1330 to travel in direction D4, and a sub-portion of display light 1332a can continue to travel in direction D4, their combination being shown as display light 1334a. At point 1336, at least a portion of display light 1334a can be redirected to travel in direction D5 in combination with display light 1335b described above, thereby increasing the brightness of display light traveling through areas where the display light would otherwise be dimmed.

[0155] As described above, shining once or twice on the uniformizing optical device 1330 is merely an example of how many times the display light may shine on the uniformizing optical device 1330, and for a given application, such as by designing the shape and area covered by the uniformizing optical device 1330, the display light may shine on the uniformizing optical device 1330 any number of times as appropriate.

[0156] Display light 1332b, display light 1334b, display light 1336b, display light 1337b, and display light 1338b can each travel in the volume of the optical combiner 1300 along a direction D5 toward an outgoing coupler region including the outgoing coupler optics 1340. Each of the display light 1332b, display light 1334b, display light 1336b, display light 1337b, and display light 1338b can impinge on the outgoing coupler optics 1340 at any suitable number of points based on, for example, the thickness of the optical combiner 1300 and / or the area of ​​the outgoing coupler optics 1340. At each point where a given portion of the display light impinges, at least a portion of the impinging display light can be redirected by the outgoing coupler optics 1340 to exit from the volume of the optical combiner such that visible display light is outcoupled to be viewed by a user, similar to as described in reference to FIG. Figure 5 , Figure 6 , Figure 8 , Fig. 9 , Fig.10 and Fig.12 as described.

[0157] Fig.13The example shows that spatially separated portions of display light from expander optics 1320 are further divided into sub-portions that are redirected to create additional exit pupils in the outgoing coupler region. For example, display light 1334b and display light 1337b travel in a region that is between the regions where display lights 1322, 1325, and 1328 would travel without uniformizing optics 1330. However, this is not required. Instead, uniformizing optics 1330 can be designed to redirect sub-portions of display light to travel in the same regions where display lights 1322, 1325, and 1328 would travel without uniformizing optics 1330. That is, sub-portions of display light can be redirected to brighten the same exit pupil that would be produced by expander optics 1320. Conversely, the homogenizing optics 1330 may be designed so that a sub-portion of the display light does not directly brighten the same exit pupil 1320 that would be produced by the expander optics, but instead merely forms a new exit pupil in the outgoing coupler region.

[0158] Fig.13 Each of the spatially separated portions of display light 1322, 1325, and 1328 is shown as impinging on uniformizing optics 1330. However, optical combiner 1300 may be designed so that not all of the spatially separated portions of display light impinge on uniformizing optics. For example, display light 1328 is darker than display light 1325 and display light 1322. Therefore, it may be undesirable for display light 1328 to impinge on uniformizing optics 1330 because this would redirect a portion of display light 1328 to travel in direction D4. As an example, the width of uniformizing optics 1330 may be small enough in the region where display light 1328 travels so that display light 1328 does not impinge on uniformizing optics 1330. As another example, uniformizing optics may not extend the full length of expander optics 1320 in direction D4.

[0159] Similar to what is mentioned above, each of the incoming coupler optics 1310, the expander optics 1320, the homogenizing optics 1330, and the outgoing coupler optics 1340 may include an optical grating, such as a surface relief grating or a holographic grating. In addition, due to the homogenizing optics 1330, the expander optics 1320 may be designed to have a higher efficiency. As mentioned above, if the efficiency of the expander optics is high, the spatially separated portions of light generated by the expander optics 1320 may not be very uniform. However, the homogenizing optics 1330 redistributes the display light to provide a more uniform display light distribution, thereby increasing the efficiency of the expander optics 1320 while still maintaining acceptable display light uniformity. Therefore, the efficiency of the optical combiner 1300 as a whole may be higher.

[0160] In some embodiments, the expander optic 1320 and the homogenizing optic 1330 can be directly adjacent to each other. In some embodiments, the expander optic 1320 and the homogenizing optic 1330 can be continuous optics. In other embodiments, the expander optic 1320 and the homogenizing optic 1330 can be separated by a gap. In some embodiments, the homogenizing optic 1330 can be implemented as a secondary optical function to the expander optic 1320, positioned in a region of the expander optic 1320 that is close to where the display light will exit the expander optic 1320 toward the outgoing coupler region.

[0161] Fig.14 is an orthogonal view showing an optical combiner 1400, which may be similar in some respects to the optical combiner 1100. Figure 8 The optical combiner 800, Fig. 9 Optical combiner 900, Fig.10 The optical combiner 1000 and Fig.13 The optical combiner 1300 in FIG. Figure 8 , Fig. 9 , Fig.10 and Fig.13 The description of the components in this section applies to Fig.14 Parts with similar numbers in . Fig.14An optical combiner 1400 is shown, which may include an incoming coupler optic 810, an expander optic 820, an outgoing coupler optic 830, a recycling optic 840, a recycling optic 940, a recycling optic 950, a recycling optic 1040, and a homogenizing optic 1330. By including at least one recycling optic in addition to at least one homogenizing optic, the optical combiner 1400 may provide greater power efficiency, display brightness, and / or display uniformity than the optical combiner 800, the optical combiner 900, the optical combiner 1000, or the optical combiner 1300. In particular, the recycling optic 840 may redirect display light that travels through the outgoing coupler region in the volume of the optical combiner 1400 without being redirected to exit from the volume of the optical combiner 1400 back toward the outgoing coupler region, similar to Figure 8 In addition, recycling optics 940 and recycling optics 950 can redirect display light that travels through the expander region in the volume of the optical combiner 1400 without being redirected toward the outgoing coupler region to travel toward the outgoing coupler region, similar to Fig. 9 1040 and recycling optics 940 and 950 in FIG. 1040. In addition, recycling optics 1040 can redirect display light traveling through the volume of optical combiner 1400 away from the outgoing coupler region to travel toward the outgoing coupler region, similar to Fig.10 Further, uniformizing optics 1330 can receive display light from expander optics 820 and redistribute brighter portions of the received display light over areas through which less display light traveled to provide a more uniform display light distribution.

[0162] Thus, optical combiner 1400 can achieve the display light recycling of optical combiner 800, optical combiner 900, and optical combiner 1000, while also achieving the display light homogenization of optical combiner 1300. In addition, recycling optics 840, recycling optics 940, recycling optics 950, recycling optics 1040, and homogenization optics 1330 need not be together in a single optical combiner. Instead, any suitable combination of recycling optics and homogenization optics may be implemented together as desired for a given application.

[0163] In some embodiments, one or more optical fibers may be used to direct optical signals along some of the paths shown herein.

[0164] The WHUD described herein may include one or more sensors (e.g., microphones, cameras, thermometers, compasses, altimeters, and / or other sensors) for collecting data from the user's environment. For example, one or more cameras may be used to provide feedback to a processor of the WHUD and influence where any given image should be displayed on the display.

[0165] The WHUD described herein may include one or more onboard power sources (e.g., one or more batteries), a wireless transceiver for sending / receiving wireless communications, and / or for coupling to a computer and / or or charging one or more onboard power sources.

[0166] The WHUD described herein may receive and respond to commands from a user in one or more of a variety of ways, including, but not limited to: voice commands via a microphone; touch commands via buttons, switches, or touch-sensitive surfaces; and / or gesture-based commands via a gesture detection system.

[0167] Throughout this specification and the appended claims, the term "communication" as in "communication path," "communicative coupling," and variations such as "communicatively coupled" is generally used to refer to any engineering arrangement for transmitting and / or exchanging information. Exemplary communication paths include, but are not limited to, conductive paths (e.g., conductive wires, conductive traces), magnetic paths (e.g., magnetic media), and / or optical paths (e.g., optical fibers), and exemplary communication path couplings include, but are not limited to, electrical couplings, magnetic couplings, and / or optical couplings.

[0168] In this specification and the appended claims, infinitive verb forms are often used. Examples include, but are not limited to: "for detecting", "for providing", "for transmitting", "for communicating", "for processing", "for routing", etc. Unless the specific context requires otherwise, such infinitive verb forms are used in an open inclusive sense, i.e., "at least to detect", "at least to provide", "at least to transmit", etc.

[0169] The above description of the illustrated embodiments, including what is described in the Abstract, is not intended to be exhaustive or to limit the embodiments to the precise forms disclosed. Although specific embodiments and examples are described herein for illustrative purposes, various equivalent modifications may be made without departing from the spirit and scope of the present disclosure, as will be recognized by those skilled in the relevant art. The teachings provided herein of various embodiments may be applied to other portable and / or wearable electronic devices, not necessarily the exemplary wearable electronic devices generally described above.

[0170] For example, the foregoing detailed description has been used to illustrate various embodiments of devices and / or processes by using block diagrams, schematic diagrams, and examples. As long as such block diagrams, schematic diagrams, and examples contain one or more functions and / or operations, those skilled in the art will understand that each function and / or operation in such block diagrams, flow charts, or examples can be implemented individually and / or in general by various hardware, software, firmware, or almost any combination thereof.

[0171] In some embodiments, certain aspects of the above-mentioned technology can be implemented by one or more processors of a processing system that executes software. The software includes one or more sets of executable instructions stored or otherwise tangibly implemented on a non-transitory computer-readable storage medium. The software may include instructions and certain data, and when these instructions and certain data are executed by one or more processors, these instructions and certain data manipulate one or more processors to perform one or more forms of the above-mentioned technology. Non-transitory computer-readable storage media may include, for example, magnetic or optical disk storage devices, solid-state storage devices, such as flash memory, cache, random access memory (RAM) or other non-volatile storage devices, etc. The executable instructions stored on the non-transitory computer-readable storage medium may be source code, assembly language code, object code, or other instruction formats that can be interpreted or otherwise executed by one or more processors.

[0172] Computer-readable storage media may include any storage media or combination of storage media that can be accessed by a computer system during use to provide instructions and / or data to the computer system. Such storage media may include, but are not limited to, optical media (e.g., compact disk (CD), digital versatile disk (DVD), Blu-ray disc), magnetic media (e.g., floppy disk, tape, or hard magnetic drive), volatile memory (e.g., random access memory (RAM) or cache), non-volatile memory (e.g., read-only memory (ROM) or flash memory), or micro-electromechanical system (MEMS)-based storage media. Computer-readable storage media may be embedded in a computing system (e.g., system RAM or ROM), fixedly attached to a computing system (e.g., a magnetic hard drive), removably attached to a computing system (e.g., flash memory based on an optical disk or a universal serial bus (USB)), or connected to a computer system via a wired or wireless network (e.g., a network accessible storage (NAS)).

[0173] Please note that not all activities or elements described in the above general description are required, a part of a particular activity or device may not be required, and one or more additional activities may be performed or additional elements may be included in addition to those described. In addition, the order in which the activities are listed is not necessarily the order in which they are performed. In addition, these concepts have been described with reference to specific embodiments. However, it is understood by those of ordinary skill in the art that various modifications and changes may be made without departing from the scope of the present disclosure as set forth in the appended claims. Therefore, the specification and drawings should be regarded as illustrative rather than restrictive, and all such modifications are intended to be included within the scope of the present disclosure.

[0174] Benefits, other advantages, and solutions to problems have been described above for specific embodiments. However, benefits, advantages, solutions to problems, and any features that may cause any benefit, advantage, or solution to occur or become more apparent are not to be interpreted as key, essential, or basic features or elements of any and all claims. In addition, the specific embodiments disclosed above are merely illustrative, since the disclosed subject matter may be modified and practiced in different but equivalent ways for those skilled in the art who benefit from the teachings herein. Except as described in the appended claims, it is not intended to limit the details of construction or design shown herein. Therefore, it is apparent that the specific embodiments disclosed above may be changed or modified, and all such variations are considered to be within the scope of the disclosed subject matter. Therefore, the protection sought herein is as described in the appended claims.

Claims

1. An optical combiner, comprising: an incoming coupler optic for receiving display light from outside the optical combiner and redirecting the display light to travel within the volume of the optical combiner; an outgoing coupler optic for receiving the display light traveling in the volume of the optical combiner and redirecting a portion of the display light traveling in the volume of the optical combiner to exit from the volume of the optical combiner, wherein a) the incoming coupler optic redirects another portion of the display light to travel in the volume of the optical combiner away from the outgoing coupler optic; and the optical combiner comprising recycling optics for receiving a portion of display light traveling in a direction away from the outgoing coupler optics in a volume of the optical combiner and redirecting the display light traveling in a direction away from the outgoing coupler optics in the volume of the optical combiner toward the outgoing coupler optics, or, b) The optical combiner comprises: an expander optic for receiving a portion of the display light from the incoming coupler optic, the expander optic for redirecting the received portion of the display light toward the outgoing coupler optic, wherein the incoming coupler optic is for redirecting a portion of the display light away from the expander optic; and A recycling optic is provided for receiving a portion of the display light redirected away from the expander optic and for redirecting the portion of the display light toward the expander optic.

2. The optical combiner according to claim 1, wherein: The outgoing coupler optics are positioned laterally between the incoming coupler optics and the recycling optics.

3. The optical combiner according to claim 1, wherein: The incoming coupler optic is positioned laterally between the recycling optic and the outgoing coupler optic.

4. The optical combiner according to claim 1, wherein: The expander optic is positioned laterally between the recycling optic and the outgoing coupler optic.

5. The optical combiner of claim 1 , further comprising another recycling optic for receiving a portion of the display light that travels in the volume of the optical combiner to pass through the exit coupler optic without being redirected to exit from the volume of the optical combiner; and redirecting the portion of the display light to travel in the volume of the optical combiner back toward the exit coupler optic.

6. The optical combiner according to any one of claims 1 to 5, wherein: The incoming coupler optics, the outgoing coupler optics and the recycling optics are surface relief gratings.

7. The optical combiner according to any one of claims 1 to 5, wherein: The incoming coupler optics, the outgoing coupler optics and the recycling optics are optical holographic.

8. The optical combiner according to claim 5, wherein: The outgoing coupler optic is an optical grating and the further recycling optic is an optical grating and the further recycling optic has a period that is half the period of the outgoing coupler optic.

9. The optical combiner according to claim 5, wherein: The outgoing coupler optical device is a two-dimensional optical grating for receiving display light traveling in a first direction in the volume of the optical combiner, redirecting some of the display light traveling in the first direction in the volume of the optical combiner to travel through the volume of the optical combiner in a second direction that is not parallel to the first direction, and redirecting some of the display light traveling through the volume of the optical combiner in the second direction to exit from the volume of the optical combiner.

10. The optical combiner according to claim 9, wherein: At least some of the display light traveling in the first direction in the volume of the optical combiner will pass through the outgoing coupler region without being redirected to travel in the second direction, at least some of the display light traveling in the second direction will pass through the outgoing coupler region without being redirected to exit from the volume of the optical combiner, and the recycling optical device is used to receive the display light traveling in the second direction that passes through the outgoing coupler region and redirect the received display light toward the outgoing coupler region.

11. The optical combiner according to claim 5, wherein: The outgoing coupler optic and the further recycling optic are directly adjacent to each other.

12. The optical combiner according to claim 5, wherein: The outgoing coupler optic and the further recycling optic are spatially separated from each other by a gap.

13. The optical combiner according to claim 1, wherein: the incoming coupler optics for receiving the display light from outside the optical combiner and redirecting the display light to travel in a first direction within the volume of the optical combiner; The expander optical device is used to redirect a portion of the display light to travel in a second direction in the volume of the optical combiner as a plurality of spatially separated portions of display light, the second direction being non-parallel to the first direction; wherein, The optical combiner further comprises a homogenizing optic for receiving at least one of the portions of the spatially separated display light traveling in the volume of the optical combiner along the second direction, and for each portion of the spatially separated display light traveling in the volume of the optical combiner along the second direction received by the homogenizing optic, the homogenizing optic for redirecting a sub-portion of the portions of the spatially separated display light traveling in the volume of the optical combiner along the second direction to travel in the volume of the optical combiner along the first direction and subsequently redirecting the sub-portion to travel in the volume of the optical combiner along the second direction; and wherein the outgoing coupler optics is for receiving the display light travelling in the second direction in the volume of the optical combiner and redirecting the display light to exit from the volume of the optical combiner.

14. The optical combiner according to claim 13, wherein: The uniformizing optical device comprises an optical grating, wherein the uniformizing optical device has a first diffraction efficiency for a region of the uniformizing optical device close to the incoming coupler optical device, and the uniformizing optical device has a second diffraction efficiency for a region of the uniformizing optical device far from the incoming coupler optical device, wherein the first diffraction efficiency is greater than the second diffraction efficiency.

15. The optical combiner according to claim 13, wherein: For a region of the uniformizing optical device close to the incoming coupler grating, the uniformizing optical device has a first width in the second direction, and for a region of the uniformizing optical device far from the incoming coupler grating, the uniformizing optical device has a second width in the second direction, and the first width is greater than the second width.

16. An optical combiner according to any one of claims 13 to 15, wherein: The expander optics and the homogenizing optics are directly adjacent to each other.

17. An optical combiner according to any one of claims 13 to 15, wherein: The expander optics and the homogenizing optics are continuous grating regions.

18. An optical combiner according to any one of claims 13 to 15, wherein: The expander optics and the homogenizing optics are spatially separated by a gap.

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